Measuring content brightness in head worn computing

ABSTRACT

Aspects of the present invention relate to methods and systems for measuring and managing the brightness of digital content in a field of view of a head-worn computer.

CROSS REFERENCE OF RELATED APPLICATIONS

This application claims the benefit of priority to and is a continuation of U.S. Non-Provisional application Ser. No. 17/132,957, filed on Dec. 23, 2020, which is a continuation of U.S. Non-Provisional application Ser. No. 15/805,199, filed on Nov. 7, 2017, U.S. Pat. No. 10,908,422, which is a continuation of U.S. Non-Provisional application Ser. No. 14/457,853, filed Aug. 12, 2014, U.S. Pat. No. 9,829,707, which are incorporated by reference herein in their entirety.

BACKGROUND Field of the Invention

This invention relates to head worn computing. More particularly, this invention relates to technologies for the measuring and controlling the brightness of digital content in head worn computing.

Description of Related Art

Wearable computing systems have been developed and are beginning to be commercialized. Many problems persist in the wearable computing field that need to be resolved to make them meet the demands of the market.

SUMMARY

Aspects of the present invention relate to methods and systems for measuring and controlling the brightness digital content in a field of view of a head-worn computer.

These and other systems, methods, objects, features, and advantages of the present invention will be apparent to those skilled in the art from the following detailed description of the preferred embodiments and the drawings. All documents mentioned herein are hereby incorporated in their entirety by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are described with reference to the following Figures. The same numbers may be used throughout to reference like features and components that are shown in the Figures:

FIG. 1 illustrates a head worn computing system in accordance with the principles of the present invention.

FIG. 2 illustrates a head worn computing system with optical system in accordance with the principles of the present invention.

FIG. 3a illustrates a large prior art optical arrangement.

FIG. 3b illustrates an upper optical module in accordance with the principles of the present invention.

FIG. 4 illustrates an upper optical module in accordance with the principles of the present invention.

FIG. 4a illustrates an upper optical module in accordance with the principles of the present invention.

FIG. 4b illustrates an upper optical module in accordance with the principles of the present invention.

FIG. 5 illustrates an upper optical module in accordance with the principles of the present invention.

FIG. 5a illustrates an upper optical module in accordance with the principles of the present invention.

FIG. 5b illustrates an upper optical module and dark light trap according to the principles of the present invention.

FIG. 5c illustrates an upper optical module and dark light trap according to the principles of the present invention.

FIG. 5d illustrates an upper optical module and dark light trap according to the principles of the present invention.

FIG. 5e illustrates an upper optical module and dark light trap according to the principles of the present invention.

FIG. 6 illustrates upper and lower optical modules in accordance with the principles of the present invention.

FIG. 7 illustrates angles of combiner elements in accordance with the principles of the present invention.

FIG. 8 illustrates upper and lower optical modules in accordance with the principles of the present invention.

FIG. 8a illustrates upper and lower optical modules in accordance with the principles of the present invention.

FIG. 8b illustrates upper and lower optical modules in accordance with the principles of the present invention.

FIG. 8c illustrates upper and lower optical modules in accordance with the principles of the present invention.

FIG. 9 illustrates an eye imaging system in accordance with the principles of the present invention.

FIG. 10 illustrates a light source in accordance with the principles of the present invention.

FIG. 10a illustrates a back lighting system in accordance with the principles of the present invention.

FIG. 10b illustrates a back lighting system in accordance with the principles of the present invention.

FIGS. 11a to 11d illustrate light source and filters in accordance with the principles of the present invention.

FIGS. 12a to 12c illustrate light source and quantum dot systems in accordance with the principles of the present invention.

FIGS. 13a to 13c illustrate peripheral lighting systems in accordance with the principles of the present invention.

FIGS. 14a to 14c illustrate a light suppression systems in accordance with the principles of the present invention.

FIG. 15 illustrates an external user interface in accordance with the principles of the present invention.

FIGS. 16a to 16c illustrate distance control systems in accordance with the principles of the present invention.

FIGS. 17a to 17c illustrate force interpretation systems in accordance with the principles of the present invention.

FIGS. 18a to 18c illustrate user interface mode selection systems in accordance with the principles of the present invention.

FIG. 19 illustrates interaction systems in accordance with the principles of the present invention.

FIG. 20 illustrates external user interfaces in accordance with the principles of the present invention.

FIG. 21 illustrates mD trace representations presented in accordance with the principles of the present invention.

FIG. 22 illustrates mD trace representations presented in accordance with the principles of the present invention.

FIG. 23 illustrates an mD scanned environment in accordance with the principles of the present invention.

FIG. 23a illustrates mD trace representations presented in accordance with the principles of the present invention.

FIG. 24 illustrates a stray light suppression technology in accordance with the principles of the present invention.

FIG. 25 illustrates a stray light suppression technology in accordance with the principles of the present invention.

FIG. 26 illustrates a stray light suppression technology in accordance with the principles of the present invention.

FIG. 27 illustrates a stray light suppression technology in accordance with the principles of the present invention.

FIGS. 28a to 28c illustrate DLP mirror angles.

FIGS. 29 to 33 illustrate eye imaging systems according to the principles of the present invention.

FIGS. 34 and 34 a illustrate structured eye lighting systems according to the principles of the present invention.

FIG. 35 illustrates eye glint in the prediction of eye direction analysis in accordance with the principles of the present invention.

FIG. 36a illustrates eye characteristics that may be used in personal identification through analysis of a system according to the principles of the present invention.

FIG. 36b illustrates a digital content presentation reflection off of the wearer's eye that may be analyzed in accordance with the principles of the present invention.

FIG. 37 illustrates eye imaging along various virtual target lines and various focal planes in accordance with the principles of the present invention.

FIG. 38 illustrates content control with respect to eye movement based on eye imaging in accordance with the principles of the present invention.

FIG. 39 illustrates eye imaging and eye convergence in accordance with the principles of the present invention.

FIG. 40 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 41 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 42 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 43 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 44 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 45 illustrates various headings over time in an example.

FIG. 46 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 47 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 48 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 49 illustrates content position dependent on sensor feedback in accordance with the principles of the present invention.

FIG. 50 illustrates light impinging an eye in accordance with the principles of the present invention.

FIG. 51 illustrates a view of an eye in accordance with the principles of the present invention.

FIGS. 52a and 52b illustrates views of an eye with a structured light pattern in accordance with the principles of the present invention.

FIG. 53 illustrates an optics module in accordance with the principles of the present invention.

FIG. 54 illustrates an optics module in accordance with the principles of the present invention.

FIG. 55 shows a series of example spectrum for a variety of controlled substances as measured using a form of infrared spectroscopy.

FIG. 56 shows an infrared absorbance spectrum for glucose.

FIG. 57 illustrates a scene where a person is walking with a HWC mounted on his head.

FIG. 58 illustrates a system for receiving, developing and using movement heading, sight heading, eye heading and/or persistence information from HWC(s).

FIG. 59 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 60 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 61 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 62 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 63 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 64 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 65 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 66 illustrates a presentation technology in accordance with the principles of the present invention.

FIG. 67 illustrates a location based presentation technology in accordance with the principles of the present invention.

FIG. 68 illustrates a location based presentation technology in accordance with the principles of the present invention.

FIG. 69 illustrates personal setting preferences for location based content presentation in accordance with the principles of the present invention.

FIG. 70 illustrates supplemental and primary content in accordance with the principles of the present invention.

FIG. 71 illustrates group message treatment in accordance with the principles of the present invention.

FIG. 72 illustrates shared content treatment in accordance with the principles of the present invention.

FIG. 73 illustrates marker recognition activation in accordance with the principles of the present invention.

FIG. 74 illustrates content, tag and preference settings in accordance with the principles of the present invention.

FIG. 75 illustrates presentation confirmation in accordance with the principles of the present invention.

FIG. 76 illustrates presentation confirmation in accordance with the principles of the present invention.

FIG. 77 illustrates a distance determination technology for the presentation of content at a focal plane in accordance with the principles of the present invention.

FIG. 78 illustrates a distance determination technology for the presentation of content at a focal plane in accordance with the principles of the present invention.

FIG. 79 illustrates a distance determination technology for the presentation of content at a focal plane in accordance with the principles of the present invention.

While the invention has been described in connection with certain preferred embodiments, other embodiments would be understood by one of ordinary skill in the art and are encompassed herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Aspects of the present invention relate to head-worn computing (“HWC”) systems. HWC involves, in some instances, a system that mimics the appearance of head-worn glasses or sunglasses. The glasses may be a fully developed computing platform, such as including computer displays presented in each of the lenses of the glasses to the eyes of the user. In embodiments, the lenses and displays may be configured to allow a person wearing the glasses to see the environment through the lenses while also seeing, simultaneously, digital imagery, which forms an overlaid image that is perceived by the person as a digitally augmented image of the environment, or augmented reality (“AR”).

HWC involves more than just placing a computing system on a person's head. The system may need to be designed as a lightweight, compact and fully functional computer display, such as wherein the computer display includes a high resolution digital display that provides a high level of emersion comprised of the displayed digital content and the see-through view of the environmental surroundings. User interfaces and control systems suited to the HWC device may be required that are unlike those used for a more conventional computer such as a laptop. For the HWC and associated systems to be most effective, the glasses may be equipped with sensors to determine environmental conditions, geographic location, relative positioning to other points of interest, objects identified by imaging and movement by the user or other users in a connected group, and the like. The HWC may then change the mode of operation to match the conditions, location, positioning, movements, and the like, in a method generally referred to as a contextually aware HWC. The glasses also may need to be connected, wirelessly or otherwise, to other systems either locally or through a network. Controlling the glasses may be achieved through the use of an external device, automatically through contextually gathered information, through user gestures captured by the glasses sensors, and the like. Each technique may be further refined depending on the software application being used in the glasses. The glasses may further be used to control or coordinate with external devices that are associated with the glasses.

Referring to FIG. 1, an overview of the HWC system 100 is presented. As shown, the HWC system 100 comprises a HWC 102, which in this instance is configured as glasses to be worn on the head with sensors such that the HWC 102 is aware of the objects and conditions in the environment 114. In this instance, the HWC 102 also receives and interprets control inputs such as gestures and movements 116. The HWC 102 may communicate with external user interfaces 104. The external user interfaces 104 may provide a physical user interface to take control instructions from a user of the HWC 102 and the external user interfaces 104 and the HWC 102 may communicate bi-directionally to affect the user's command and provide feedback to the external device 108. The HWC 102 may also communicate bi-directionally with externally controlled or coordinated local devices 108. For example, an external user interface 104 may be used in connection with the HWC 102 to control an externally controlled or coordinated local device 108. The externally controlled or coordinated local device 108 may provide feedback to the HWC 102 and a customized GUI may be presented in the HWC 102 based on the type of device or specifically identified device 108. The HWC 102 may also interact with remote devices and information sources 112 through a network connection 110. Again, the external user interface 104 may be used in connection with the HWC 102 to control or otherwise interact with any of the remote devices 108 and information sources 112 in a similar way as when the external user interfaces 104 are used to control or otherwise interact with the externally controlled or coordinated local devices 108. Similarly, HWC 102 may interpret gestures 116 (e.g., captured from forward, downward, upward, rearward facing sensors such as camera(s), range finders, IR sensors, etc.) or environmental conditions sensed in the environment 114 to control either local or remote devices 108 or 112.

We will now describe each of the main elements depicted on FIG. 1 in more detail; however, these descriptions are intended to provide general guidance and should not be construed as limiting. Additional description of each element may also be further described herein.

The HWC 102 is a computing platform intended to be worn on a person's head. The HWC 102 may take many different forms to fit many different functional requirements. In some situations, the HWC 102 will be designed in the form of conventional glasses. The glasses may or may not have active computer graphics displays. In situations where the HWC 102 has integrated computer displays the displays may be configured as see-through displays such that the digital imagery can be overlaid with respect to the user's view of the environment 114. There are a number of see-through optical designs that may be used, including ones that have a reflective display (e.g. LCoS, DLP), emissive displays (e.g. OLED, LED, backlit LCD), hologram, TIR waveguides, and the like. In embodiments, lighting systems used in connection with the display optics may be solid state lighting systems, such as LED, OLED, quantum dot, quantum dot LED, etc. In addition, the optical configuration may be monocular or binocular. It may also include vision corrective optical components. In embodiments, the optics may be packaged as contact lenses. In other embodiments, the HWC 102 may be in the form of a helmet with a see-through shield, sunglasses, safety glasses, goggles, a mask, fire helmet with see-through shield, police helmet with see through shield, military helmet with see-through shield, utility form customized to a certain work task (e.g. inventory control, logistics, repair, maintenance, etc.), and the like.

The HWC 102 may also have a number of integrated computing facilities, such as an integrated processor, integrated power management, communication structures (e.g. cell net, WiFi, Bluetooth, local area connections, mesh connections, remote connections (e.g. client server, etc.)), and the like. The HWC 102 may also have a number of positional awareness sensors, such as GPS, electronic compass, altimeter, tilt sensor, IMU, and the like. It may also have other sensors such as a camera, rangefinder, hyper-spectral camera, Geiger counter, microphone, spectral illumination detector, temperature sensor, chemical sensor, biologic sensor, moisture sensor, ultrasonic sensor, and the like.

The HWC 102 may also have integrated control technologies. The integrated control technologies may be contextual based control, passive control, active control, user control, and the like. For example, the HWC 102 may have an integrated sensor (e.g. camera, IR structured light emission with related sensor system) that captures user hand or body gestures 116 such that the integrated processing system can interpret the gestures and generate control commands for the HWC 102. In another example, the HWC 102 may have sensors that detect movement (e.g. a nod, head shake, and the like) including accelerometers, gyros and other inertial measurements, where the integrated processor may interpret the movement and generate a control command in response. The HWC 102 may also automatically control itself based on measured or perceived environmental conditions. For example, if it is bright in the environment the HWC 102 may increase the brightness or contrast of the displayed image. In embodiments, the integrated control technologies may be mounted on the HWC 102 such that a user can interact with it directly. For example, the HWC 102 may have a button(s), touch capacitive interface, and the like.

As described herein, the HWC 102 may be in communication with external user interfaces 104. The external user interfaces may come in many different forms. For example, a cell phone screen may be adapted to take user input for control of an aspect of the HWC 102. The external user interface may be a dedicated UI, such as a keyboard, touch surface, button(s), joy stick, and the like. In embodiments, the external controller may be integrated into another device such as a ring, watch, pen, bike, car, application specific device and the like. In each case, the external user interface 104 may include sensors (e.g. IMU, accelerometers, compass, altimeter, and the like) to provide additional input for controlling the HWD 104.

As described herein, the HWC 102 may control or coordinate with other local devices 108. The external devices 108 may be an audio device, visual device, vehicle, cell phone, computer, and the like. For instance, the local external device 108 may be another HWC 102, where information may then be exchanged between the separate HWCs 108.

Similar to the way the HWC 102 may control or coordinate with local devices 106, the HWC 102 may control or coordinate with remote devices 112, such as the HWC 102 communicating with the remote devices 112 through a network 110. Again, the form of the remote device 112 may have many forms. Included in these forms is another HWC 102. For example, each HWC 102 may communicate its GPS position such that all the HWCs 102 know where all of HWC 102 are located.

FIG. 2 illustrates a HWC 102 with an optical system that includes an upper optical module 202 and a lower optical module 204. While the upper and lower optical modules 202 and 204 will generally be described as separate modules, it should be understood that this is illustrative only and the present invention includes other physical configurations, such as that when the two modules are combined into a single module or where the elements making up the two modules are configured into more than two modules. In embodiments, the upper module 202 includes a computer controlled display (e.g. LCoS, DLP, OLED, backlit LCD, etc.) and image light delivery optics. In embodiments, the lower module includes eye delivery optics that are configured to receive the upper module's image light and deliver the image light to the eye of a wearer of the HWC. In FIG. 2, it should be noted that while the upper and lower optical modules 202 and 204 are illustrated in one side of the HWC such that image light can be delivered to one eye of the wearer, that it is envisioned by the present invention that embodiments will contain two image light delivery systems, one for each eye.

FIG. 3b illustrates an upper optical module 202 in accordance with the principles of the present invention. In this embodiment, the upper optical module 202 includes a DLP (also known as DMD or digital micromirror device) computer operated display 304 which includes pixels comprised of rotatable mirrors (such as, for example, the DLP3000 available from Texas Instruments), polarized light source 302, ¼ wave retarder film 308, reflective polarizer 310 and a field lens 312. The polarized light source 302 provides substantially uniform polarized light that is generally directed towards the reflective polarizer 310. The reflective polarizer reflects light of one polarization state (e.g. S polarized light) and transmits light of the other polarization state (e.g. P polarized light). The polarized light source 302 and the reflective polarizer 310 are oriented so that the polarized light from the polarized light source 302 is reflected generally towards the DLP 304. The light then passes through the ¼ wave film 308 once before illuminating the pixels of the DLP 304 and then again after being reflected by the pixels of the DLP 304. In passing through the ¼ wave film 308 twice, the light is converted from one polarization state to the other polarization state (e.g. the light is converted from S to P polarized light). The light then passes through the reflective polarizer 310. In the event that the DLP pixel(s) are in the “on” state (i.e. the mirrors are positioned to reflect light towards the field lens 312, the “on” pixels reflect the light generally along the optical axis and into the field lens 312. This light that is reflected by “on” pixels and which is directed generally along the optical axis of the field lens 312 will be referred to as image light 316. The image light 316 then passes through the field lens to be used by a lower optical module 204.

The light that is provided by the polarized light source 302, which is subsequently reflected by the reflective polarizer 310 before it reflects from the DLP 304, will generally be referred to as illumination light. The light that is reflected by the “off” pixels of the DLP 304 is reflected at a different angle than the light reflected by the “on” pixels, so that the light from the “off” pixels is generally directed away from the optical axis of the field lens 312 and toward the side of the upper optical module 202 as shown in FIG. 3. The light that is reflected by the “off” pixels of the DLP 304 will be referred to as dark state light 314.

The DLP 304 operates as a computer controlled display and is generally thought of as a MEMs device. The DLP pixels are comprised of small mirrors that can be directed. The mirrors generally flip from one angle to another angle. The two angles are generally referred to as states. When light is used to illuminate the DLP the mirrors will reflect the light in a direction depending on the state. In embodiments herein, we generally refer to the two states as “on” and “off,” which is intended to depict the condition of a display pixel. “On” pixels will be seen by a viewer of the display as emitting light because the light is directed along the optical axis and into the field lens and the associated remainder of the display system. “Off” pixels will be seen by a viewer of the display as not emitting light because the light from these pixels is directed to the side of the optical housing and into a light trap or light dump where the light is absorbed. The pattern of “on” and “off” pixels produces image light that is perceived by a viewer of the display as a computer generated image. Full color images can be presented to a user by sequentially providing illumination light with complimentary colors such as red, green and blue. Where the sequence is presented in a recurring cycle that is faster than the user can perceive as separate images and as a result the user perceives a full color image comprised of the sum of the sequential images. Bright pixels in the image are provided by pixels that remain in the “on” state for the entire time of the cycle, while dimmer pixels in the image are provided by pixels that switch between the “on” state and “off” state within the time of the cycle, or frame time when in a video sequence of images.

FIG. 3a shows an illustration of a system for a DLP 304 in which the unpolarized light source 350 is pointed directly at the DLP 304. In this case, the angle required for the illumination light is such that the field lens 352 must be positioned substantially distant from the DLP 304 to avoid the illumination light from being clipped by the field lens 352. The large distance between the field lens 352 and the DLP 304 along with the straight path of the dark state light 354, means that the light trap for the dark state light 354 is also located at a substantial distance from the DLP. For these reasons, this configuration is larger in size compared to the upper optics module 202 of the preferred embodiments of the present invention.

The configuration illustrated in FIG. 3b can be lightweight and compact such that it fits into a small portion of a HWC. For example, the upper modules 202 illustrated herein can be physically adapted to mount in an upper frame of a HWC such that the image light can be directed into a lower optical module 204 for presentation of digital content to a wearer's eye. The package of components that combine to generate the image light (i.e. the polarized light source 302, DLP 304, reflective polarizer 310 and ¼ wave film 308) is very light and is compact. The height of the system, excluding the field lens, may be less than 8 mm. The width (i.e. from front to back) may be less than 8 mm. The weight may be less than 2 grams. The compactness of this upper optical module 202 allows for a compact mechanical design of the HWC and the light weight nature of these embodiments help make the HWC lightweight to provide for a HWC that is comfortable for a wearer of the HWC.

The configuration illustrated in FIG. 3b can produce sharp contrast, high brightness and deep blacks, especially when compared to LCD or LCoS displays used in HWC. The “on” and “off” states of the DLP provide for a strong differentiator in the light reflection path representing an “on” pixel and an “off” pixel. As will be discussed in more detail below, the dark state light from the “off” pixel reflections can be managed to reduce stray light in the display system to produce images with high contrast.

FIG. 4 illustrates another embodiment of an upper optical module 202 in accordance with the principles of the present invention. This embodiment includes a light source 404, but in this case, the light source can provide unpolarized illumination light. The illumination light from the light source 404 is directed into a TIR wedge 418 such that the illumination light is incident on an internal surface of the TIR wedge 418 (shown as the angled lower surface of the TRI wedge 418 in FIG. 4) at an angle that is beyond the critical angle as defined by Eqn 1.

Critical angle=arc-sin(1/n)  Eqn 1

Where the critical angle is the angle beyond which the illumination light is reflected from the internal surface when the internal surface comprises an interface from a solid with a higher refractive index (n) to air with a refractive index of 1 (e.g. for an interface of acrylic, with a refractive index of n=1.5, to air, the critical angle is 41.8 degrees; for an interface of polycarbonate, with a refractive index of n=1.59, to air the critical angle is 38.9 degrees). Consequently, the TIR wedge 418 is associated with a thin air gap 408 along the internal surface to create an interface between a solid with a higher refractive index and air. By choosing the angle of the light source 404 relative to the DLP 402 in correspondence to the angle of the internal surface of the TIR wedge 418, illumination light is turned toward the DLP 402 at an angle suitable for providing image light 414 as reflected from “on” pixels. Wherein, the illumination light is provided to the DLP 402 at approximately twice the angle of the pixel mirrors in the DLP 402 that are in the “on” state, such that after reflecting from the pixel mirrors, the image light 414 is directed generally along the optical axis of the field lens. Depending on the state of the DLP pixels, the illumination light from “on” pixels may be reflected as image light 414 which is directed towards a field lens and a lower optical module 204, while illumination light reflected from “off” pixels (generally referred to herein as “dark” state light, “off” pixel light or “off” state light) 410 is directed in a separate direction, which may be trapped and not used for the image that is ultimately presented to the wearer's eye.

The light trap for the dark state light 410 may be located along the optical axis defined by the direction of the dark state light 410 and in the side of the housing, with the function of absorbing the dark state light. To this end, the light trap may be comprised of an area outside of the cone of image light 414 from the “on” pixels. The light trap is typically made up of materials that absorb light including coatings of black paints or other light absorbing materials to prevent light scattering from the dark state light degrading the image perceived by the user. In addition, the light trap may be recessed into the wall of the housing or include masks or guards to block scattered light and prevent the light trap from being viewed adjacent to the displayed image.

The embodiment of FIG. 4 also includes a corrective wedge 420 to correct the effect of refraction of the image light 414 as it exits the TIR wedge 418. By including the corrective wedge 420 and providing a thin air gap 408 (e.g. 25 micron), the image light from the “on” pixels can be maintained generally in a direction along the optical axis of the field lens (i.e. the same direction as that defined by the image light 414) so it passes into the field lens and the lower optical module 204. As shown in FIG. 4, the image light 414 from the “on” pixels exits the corrective wedge 420 generally perpendicular to the surface of the corrective wedge 420 while the dark state light exits at an oblique angle. As a result, the direction of the image light 414 from the “on” pixels is largely unaffected by refraction as it exits from the surface of the corrective wedge 420. In contrast, the dark state light 410 is substantially changed in direction by refraction when the dark state light 410 exits the corrective wedge 420.

The embodiment illustrated in FIG. 4 has the similar advantages of those discussed in connection with the embodiment of FIG. 3b . The dimensions and weight of the upper module 202 depicted in FIG. 4 may be approximately 8×8 mm with a weight of less than 3 grams. A difference in overall performance between the configuration illustrated in FIG. 3b and the configuration illustrated in FIG. 4 is that the embodiment of FIG. 4 doesn't require the use of polarized light as supplied by the light source 404. This can be an advantage in some situations as will be discussed in more detail below (e.g. increased see-through transparency of the HWC optics from the user's perspective). Polarized light may be used in connection with the embodiment depicted in FIG. 4, in embodiments. An additional advantage of the embodiment of FIG. 4 compared to the embodiment shown in FIG. 3b is that the dark state light (shown as DLP off light 410) is directed at a steeper angle away from the optical axis of the image light 414 due to the added refraction encountered when the dark state light 410 exits the corrective wedge 420. This steeper angle of the dark state light 410 allows for the light trap to be positioned closer to the DLP 402 so that the overall size of the upper module 202 can be reduced. The light trap can also be made larger since the light trap doesn't interfere with the field lens, thereby the efficiency of the light trap can be increased and as a result, stray light can be reduced and the contrast of the image perceived by the user can be increased. FIG. 4a illustrates the embodiment described in connection with FIG. 4 with an example set of corresponding angles at the various surfaces with the reflected angles of a ray of light passing through the upper optical module 202. In this example, the DLP mirrors are provided at 17 degrees to the surface of the DLP device. The angles of the TIR wedge are selected in correspondence to one another to provide TIR reflected illumination light at the correct angle for the DLP mirrors while allowing the image light and dark state light to pass through the thin air gap, various combinations of angles are possible to achieve this.

FIG. 5 illustrates yet another embodiment of an upper optical module 202 in accordance with the principles of the present invention. As with the embodiment shown in FIG. 4, the embodiment shown in FIG. 5 does not require the use of polarized light. Polarized light may be used in connection with this embodiment, but it is not required. The optical module 202 depicted in FIG. 5 is similar to that presented in connection with FIG. 4; however, the embodiment of FIG. 5 includes an off light redirection wedge 502. As can be seen from the illustration, the off light redirection wedge 502 allows the image light 414 to continue generally along the optical axis toward the field lens and into the lower optical module 204 (as illustrated). However, the off light 504 is redirected substantially toward the side of the corrective wedge 420 where it passes into the light trap. This configuration may allow further height compactness in the HWC because the light trap (not illustrated) that is intended to absorb the off light 504 can be positioned laterally adjacent the upper optical module 202 as opposed to below it. In the embodiment depicted in FIG. 5, there is a thin air gap between the TIR wedge 418 and the corrective wedge 420 (similar to the embodiment of FIG. 4). There is also a thin air gap between the corrective wedge 420 and the off light redirection wedge 502. There may be HWC mechanical configurations that warrant the positioning of a light trap for the dark state light elsewhere and the illustration depicted in FIG. 5 should be considered illustrative of the concept that the off light can be redirected to create compactness of the overall HWC. FIG. 5a illustrates an example of the embodiment described in connection with FIG. 5 with the addition of more details on the relative angles at the various surfaces and a light ray trace for image light and a light ray trace for dark light are shown as it passes through the upper optical module 202. Again, various combinations of angles are possible.

FIG. 4b shows an illustration of a further embodiment in which a solid transparent matched set of wedges 456 is provided with a reflective polarizer 450 at the interface between the wedges. Wherein the interface between the wedges in the wedge set 456 is provided at an angle so that illumination light 452 from the polarized light source 458 is reflected at the proper angle (e.g. 34 degrees for a 17 degree DLP mirror) for the DLP mirror “on” state so that the reflected image light 414 is provided along the optical axis of the field lens. The general geometry of the wedges in the wedge set 456 is similar to that shown in FIGS. 4 and 4 a. A quarter wave film 454 is provided on the DLP 402 surface so that the illumination light 452 is one polarization state (e.g. S polarization state) while in passing through the quarter wave film 454, reflecting from the DLP mirror and passing back through the quarter wave film 454, the image light 414 is converted to the other polarization state (e.g. P polarization state). The reflective polarizer is oriented such that the illumination light 452 with its polarization state is reflected and the image light 414 with its other polarization state is transmitted. Since the dark state light from the “off” pixels 410 also passes through the quarter wave film 454 twice, it is also the other polarization state (e.g. P polarization state) so that it is transmitted by the reflective polarizer 450.

The angles of the faces of the wedge set 450 correspond to the needed angles to provide illumination light 452 at the angle needed by the DLP mirrors when in the “on” state so that the reflected image light 414 is reflected from the DLP along the optical axis of the field lens. The wedge set 456 provides an interior interface where a reflective polarizer film can be located to redirect the illumination light 452 toward the mirrors of the DLP 402. The wedge set also provides a matched wedge on the opposite side of the reflective polarizer 450 so that the image light 414 from the “on” pixels exits the wedge set 450 substantially perpendicular to the exit surface, while the dark state light from the “off” pixels 410 exits at an oblique angle to the exit surface. As a result, the image light 414 is substantially unrefracted upon exiting the wedge set 456, while the dark state light from the “off” pixels 410 is substantially refracted upon exiting the wedge set 456 as shown in FIG. 4 b.

By providing a solid transparent matched wedge set, the flatness of the interface is reduced, because variations in the flatness have a negligible effect as long as they are within the cone angle of the illuminating light 452, which can be f#2.2 with a 26 degree cone angle. In a preferred embodiment, the reflective polarizer is bonded between the matched internal surfaces of the wedge set 456 using an optical adhesive so that Fresnel reflections at the interfaces on either side of the reflective polarizer 450 are reduced. The optical adhesive can be matched in refractive index to the material of the wedge set 456 and the pieces of the wedge set 456 can be all made from the same material such as BK7 glass or cast acrylic. Wherein the wedge material can be selected to have low birefringence as well to reduce non-uniformities in brightness. The wedge set 456 and the quarter wave film 454 can also be bonded to the DLP 402 to further reduce Fresnel reflections at the DLP interface losses. In addition, since the image light 414 is substantially normal to the exit surface of the wedge set 456, the flatness of the surface is not critical to maintain the wavefront of the image light 414 so that high image quality can be obtained in the displayed image without requiring very tightly toleranced flatness on the exit surface.

A yet further embodiment of the invention that is not illustrated, combines the embodiments illustrated in FIG. 4b and FIG. 5. In this embodiment, the wedge set 456 is comprised of three wedges with the general geometry of the wedges in the wedge set corresponding to that shown in FIGS. 5 and 5 a. A reflective polarizer is bonded between the first and second wedges similar to that shown in FIG. 4b , however, a third wedge is provided similar to the embodiment of FIG. 5. Wherein there is an angled thin air gap between the second and third wedges so that the dark state light is reflected by TIR toward the side of the second wedge where it is absorbed in a light trap. This embodiment, like the embodiment shown in FIG. 4b , uses a polarized light source as has been previously described. The difference in this embodiment is that the image light is transmitted through the reflective polarizer and is transmitted through the angled thin air gap so that it exits normal to the exit surface of the third wedge.

FIG. 5b illustrates an upper optical module 202 with a dark light trap 514 a. As described in connection with FIGS. 4 and 4 a, image light can be generated from a DLP when using a TIR and corrective lens configuration. The upper module may be mounted in a HWC housing 510 and the housing 510 may include a dark light trap 514 a. The dark light trap 514 a is generally positioned/constructed/formed in a position that is optically aligned with the dark light optical axis 512. As illustrated, the dark light trap may have depth such that the trap internally reflects dark light in an attempt to further absorb the light and prevent the dark light from combining with the image light that passes through the field lens. The dark light trap may be of a shape and depth such that it absorbs the dark light. In addition, the dark light trap 514 b, in embodiments, may be made of light absorbing materials or coated with light absorbing materials. In embodiments, the recessed light trap 514 a may include baffles to block a view of the dark state light. This may be combined with black surfaces and textured or fibrous surfaces to help absorb the light. The baffles can be part of the light trap, associated with the housing, or field lens, etc.

FIG. 5c illustrates another embodiment with a light trap 514 b. As can be seen in the illustration, the shape of the trap is configured to enhance internal reflections within the light trap 514 b to increase the absorption of the dark light 512. FIG. 5d illustrates another embodiment with a light trap 514 c. As can be seen in the illustration, the shape of the trap 514 c is configured to enhance internal reflections to increase the absorption of the dark light 512.

FIG. 5e illustrates another embodiment of an upper optical module 202 with a dark light trap 514 d. This embodiment of upper module 202 includes an off light reflection wedge 502, as illustrated and described in connection with the embodiment of FIGS. 5 and 5 a. As can be seen in FIG. 5e , the light trap 514 d is positioned along the optical path of the dark light 512. The dark light trap 514 d may be configured as described in other embodiments herein. The embodiment of the light trap 514 d illustrated in FIG. 5e includes a black area on the side wall of the wedge, wherein the side wall is located substantially away from the optical axis of the image light 414. In addition, baffles 5252 may be added to one or more edges of the field lens 312 to block the view of the light trap 514 d adjacent to the displayed image seen by the user.

FIG. 6 illustrates a combination of an upper optical module 202 with a lower optical module 204. In this embodiment, the image light projected from the upper optical module 202 may or may not be polarized. The image light is reflected off a flat combiner element 602 such that it is directed towards the user's eye. Wherein, the combiner element 602 is a partial mirror that reflects image light while transmitting a substantial portion of light from the environment so the user can look through the combiner element and see the environment surrounding the HWC.

The combiner 602 may include a holographic pattern, to form a holographic mirror. If a monochrome image is desired, there may be a single wavelength reflection design for the holographic pattern on the surface of the combiner 602. If the intention is to have multiple colors reflected from the surface of the combiner 602, a multiple wavelength holographic mirror may be included on the combiner surface. For example, in a three-color embodiment, where red, green and blue pixels are generated in the image light, the holographic mirror may be reflective to wavelengths substantially matching the wavelengths of the red, green and blue light provided by the light source. This configuration can be used as a wavelength specific mirror where pre-determined wavelengths of light from the image light are reflected to the user's eye. This configuration may also be made such that substantially all other wavelengths in the visible pass through the combiner element 602 so the user has a substantially clear view of the surroundings when looking through the combiner element 602. The transparency between the user's eye and the surrounding may be approximately 80% when using a combiner that is a holographic mirror. Wherein holographic mirrors can be made using lasers to produce interference patterns in the holographic material of the combiner where the wavelengths of the lasers correspond to the wavelengths of light that are subsequently reflected by the holographic mirror.

In another embodiment, the combiner element 602 may include a notch mirror comprised of a multilayer coated substrate wherein the coating is designed to substantially reflect the wavelengths of light provided by the light source and substantially transmit the remaining wavelengths in the visible spectrum. For example, in the case where red, green and blue light is provided by the light source to enable full color images to be provided to the user, the notch mirror is a tristimulus notch mirror wherein the multilayer coating is designed to reflect narrow bands of red, green and blue light that are matched to the what is provided by the light source and the remaining visible wavelengths are transmitted through the coating to enable a view of the environment through the combiner. In another example where monochrome images are provided to the user, the notch mirror is designed to reflect a single narrow band of light that is matched to the wavelength range of the light provided by the light source while transmitting the remaining visible wavelengths to enable a see-through view of the environment. The combiner 602 with the notch mirror would operate, from the user's perspective, in a manner similar to the combiner that includes a holographic pattern on the combiner element 602. The combiner, with the tristimulus notch mirror, would reflect the “on” pixels to the eye because of the match between the reflective wavelengths of the notch mirror and the color of the image light, and the wearer would be able to see with high clarity the surroundings. The transparency between the user's eye and the surrounding may be approximately 80% when using the tristimulus notch mirror. In addition, the image provided by the upper optical module 202 with the notch mirror combiner can provide higher contrast images than the holographic mirror combiner due to less scattering of the imaging light by the combiner.

Light can escape through the combiner 602 and may produce face glow as the light is generally directed downward onto the cheek of the user. When using a holographic mirror combiner or a tristimulus notch mirror combiner, the escaping light can be trapped to avoid face glow. In embodiments, if the image light is polarized before the combiner, a linear polarizer can be laminated, or otherwise associated, to the combiner, with the transmission axis of the polarizer oriented relative to the polarized image light so that any escaping image light is absorbed by the polarizer. In embodiments, the image light would be polarized to provide S polarized light to the combiner for better reflection. As a result, the linear polarizer on the combiner would be oriented to absorb S polarized light and pass P polarized light. This provides the preferred orientation of polarized sunglasses as well.

If the image light is unpolarized, a microlouvered film such as a privacy filter can be used to absorb the escaping image light while providing the user with a see-through view of the environment. In this case, the absorbance or transmittance of the microlouvered film is dependent on the angle of the light. Where steep angle light is absorbed and light at less of an angle is transmitted. For this reason, in an embodiment, the combiner with the microlouver film is angled at greater than 45 degrees to the optical axis of the image light (e.g. the combiner can be oriented at 50 degrees so the image light from the file lens is incident on the combiner at an oblique angle.

FIG. 7 illustrates an embodiment of a combiner element 602 at various angles when the combiner element 602 includes a holographic mirror. Normally, a mirrored surface reflects light at an angle equal to the angle that the light is incident to the mirrored surface. Typically, this necessitates that the combiner element be at 45 degrees, 602 a, if the light is presented vertically to the combiner so the light can be reflected horizontally towards the wearer's eye. In embodiments, the incident light can be presented at angles other than vertical to enable the mirror surface to be oriented at other than 45 degrees, but in all cases wherein a mirrored surface is employed (including the tristimulus notch mirror described previously), the incident angle equals the reflected angle. As a result, increasing the angle of the combiner 602 a requires that the incident image light be presented to the combiner 602 a at a different angle which positions the upper optical module 202 to the left of the combiner as shown in FIG. 7. In contrast, a holographic mirror combiner, included in embodiments, can be made such that light is reflected at a different angle from the angle that the light is incident onto the holographic mirrored surface. This allows freedom to select the angle of the combiner element 602 b independent of the angle of the incident image light and the angle of the light reflected into the wearer's eye. In embodiments, the angle of the combiner element 602 b is greater than 45 degrees (shown in FIG. 7) as this allows a more laterally compact HWC design. The increased angle of the combiner element 602 b decreases the front to back width of the lower optical module 204 and may allow for a thinner HWC display (i.e. the furthest element from the wearer's eye can be closer to the wearer's face).

FIG. 8 illustrates another embodiment of a lower optical module 204. In this embodiment, polarized image light provided by the upper optical module 202, is directed into the lower optical module 204. The image light reflects off a polarized mirror 804 and is directed to a focusing partially reflective mirror 802, which is adapted to reflect the polarized light. An optical element such as a ¼ wave film located between the polarized mirror 804 and the partially reflective mirror 802, is used to change the polarization state of the image light such that the light reflected by the partially reflective mirror 802 is transmitted by the polarized mirror 804 to present image light to the eye of the wearer. The user can also see through the polarized mirror 804 and the partially reflective mirror 802 to see the surrounding environment. As a result, the user perceives a combined image comprised of the displayed image light overlaid onto the see-through view of the environment.

While many of the embodiments of the present invention have been referred to as upper and lower modules containing certain optical components, it should be understood that the image light and dark light production and management functions described in connection with the upper module may be arranged to direct light in other directions (e.g. upward, sideward, etc.). In embodiments, it may be preferred to mount the upper module 202 above the wearer's eye, in which case the image light would be directed downward. In other embodiments it may be preferred to produce light from the side of the wearer's eye, or from below the wearer's eye. In addition, the lower optical module is generally configured to deliver the image light to the wearer's eye and allow the wearer to see through the lower optical module, which may be accomplished through a variety of optical components and is generally configured to receive the image light from the upper module from whatever position the upper module is mounted.

FIG. 8a illustrates an embodiment of the present invention where the upper optical module 202 is arranged to direct image light into a TIR waveguide 810. In this embodiment, the upper optical module 202 is positioned above the wearer's eye 812 and the light is directed horizontally into the TIR waveguide 810. The TIR waveguide is designed to internally reflect the image light in a series of downward TIR reflections until it reaches the portion in front of the wearer's eye, where the light passes out of the TIR waveguide 812 into the wearer's eye. In this embodiment, an outer shield 814 is positioned in front of the TIR waveguide 810.

FIG. 8b illustrates an embodiment of the present invention where the upper optical module 202 is arranged to direct image light into a TIR waveguide 818. In this embodiment, the upper optical module 202 is arranged on the side of the TIR waveguide 818. For example, the upper optical module may be positioned in the arm or near the arm of the HWC when configured as a pair of head worn glasses. The TIR waveguide 818 is designed to internally reflect the image light in a series of TIR reflections until it reaches the portion in front of the wearer's eye, where the light passes out of the TIR waveguide 812 into the wearer's eye.

FIG. 8e illustrates yet further embodiments of the present invention where an upper optical module 202 is directing polarized image light into an optical guide 828 where the image light passes through a polarized reflector 824, changes polarization state upon reflection of the optical element 822 which includes a ¼ wave film for example and then is reflected by the polarized reflector 824 towards the wearer's eye, due to the change in polarization of the image light. The upper optical module 202 may be positioned to direct light to a mirror 820, to position the upper optical module 202 laterally, in other embodiments, the upper optical module 202 may direct the image light directly towards the polarized reflector 824. It should be understood that the present invention comprises other optical arrangements intended to direct image light into the wearer's eye.

Another aspect of the present invention relates to eye imaging. In embodiments, a camera is used in connection with an upper optical module 202 such that the wearer's eye can be imaged using pixels in the “off” state on the DLP. FIG. 9 illustrates a system where the eye imaging camera 802 is mounted and angled such that the field of view of the eye imaging camera 802 is redirected toward the wearer's eye by the mirror pixels of the DLP 402 that are in the “off” state. In this way, the eye imaging camera 802 can be used to image the wearer's eye along the same optical axis as the displayed image that is presented to the wearer. Wherein, image light that is presented to the wearer's eye illuminates the wearer's eye so that the eye can be imaged by the eye imaging camera 802. In the process, the light reflected by the eye passes back though the optical train of the lower optical module 204 and a portion of the upper optical module to where the light is reflected by the “off” pixels of the DLP 402 toward the eye imaging camera 802.

In embodiments, the eye imaging camera may image the wearer's eye at a moment in time where there are enough “off” pixels to achieve the required eye image resolution. In another embodiment, the eye imaging camera collects eye image information from “off” pixels over time and forms a time lapsed image. In another embodiment, a modified image is presented to the user wherein enough “off” state pixels are included that the camera can obtain the desired resolution and brightness for imaging the wearer's eye and the eye image capture is synchronized with the presentation of the modified image.

The eye imaging system may be used for security systems. The HWC may not allow access to the HWC or other system if the eye is not recognized (e.g. through eye characteristics including retina or iris characteristics, etc.). The HWC may be used to provide constant security access in some embodiments. For example, the eye security confirmation may be a continuous, near-continuous, real-time, quasi real-time, periodic, etc. process so the wearer is effectively constantly being verified as known. In embodiments, the HWC may be worn and eye security tracked for access to other computer systems.

The eye imaging system may be used for control of the HWC. For example, a blink, wink, or particular eye movement may be used as a control mechanism for a software application operating on the HWC or associated device.

The eye imaging system may be used in a process that determines how or when the HWC 102 delivers digitally displayed content to the wearer. For example, the eye imaging system may determine that the user is looking in a direction and then HWC may change the resolution in an area of the display or provide some content that is associated with something in the environment that the user may be looking at. Alternatively, the eye imaging system may identify different users and change the displayed content or enabled features provided to the user. Users may be identified from a database of users eye characteristics either located on the HWC 102 or remotely located on the network 110 or on a server 112. In addition, the HWC may identify a primary user or a group of primary users from eye characteristics wherein the primary user(s) are provided with an enhanced set of features and all other users are provided with a different set of features. Thus in this use case, the HWC 102 uses identified eye characteristics to either enable features or not and eye characteristics need only be analyzed in comparison to a relatively small database of individual eye characteristics.

FIG. 10 illustrates a light source that may be used in association with the upper optics module 202 (e.g. polarized light source if the light from the solid state light source is polarized such as polarized light source 302 and 458), and light source 404. In embodiments, to provide a uniform surface of light 1008 to be directed into the upper optical module 202 and towards the DLP of the upper optical module, either directly or indirectly, the solid state light source 1002 may be projected into a backlighting optical system 1004. The solid state light source 1002 may be one or more LEDs, laser diodes, OLEDs. In embodiments, the backlighting optical system 1004 includes an extended section with a length/distance ratio of greater than 3, wherein the light undergoes multiple reflections from the sidewalls to mix of homogenize the light as supplied by the solid state light source 1002. The backlighting optical system 1004 can also include structures on the surface opposite (on the left side as shown in FIG. 10) to where the uniform light 1008 exits the backlight 1004 to change the direction of the light toward the DLP 302 and the reflective polarizer 310 or the DLP 402 and the TIR wedge 418. The backlighting optical system 1004 may also include structures to collimate the uniform light 1008 to provide light to the DLP with a smaller angular distribution or narrower cone angle. Diffusers or polarizers can be used on the entrance or exit surface of the backlighting optical system. Diffusers can be used to spread or uniformize the exiting light from the backlight to improve the uniformity or increase the angular spread of the uniform light 1008. Elliptical diffusers that diffuse the light more in some directions and less in others can be used to improve the uniformity or spread of the uniform light 1008 in directions orthogonal to the optical axis of the uniform light 1008. Linear polarizers can be used to convert unpolarized light as supplied by the solid state light source 1002 to polarized light so the uniform light 1008 is polarized with a desired polarization state. A reflective polarizer can be used on the exit surface of the backlight 1004 to polarize the uniform light 1008 to the desired polarization state, while reflecting the other polarization state back into the backlight where it is recycled by multiple reflections within the backlight 1004 and at the solid state light source 1002. Therefore by including a reflective polarizer at the exit surface of the backlight 1004, the efficiency of the polarized light source is improved.

FIGS. 10a and 10b show illustrations of structures in backlight optical systems 1004 that can be used to change the direction of the light provided to the entrance face 1045 by the light source and then collimates the light in a direction lateral to the optical axis of the exiting uniform light 1008. Structure 1060 includes an angled sawtooth pattern in a transparent waveguide wherein the left edge of each sawtooth clips the steep angle rays of light thereby limiting the angle of the light being redirected. The steep surface at the right (as shown) of each sawtooth then redirects the light so that it reflects off the left angled surface of each sawtooth and is directed toward the exit surface 1040. The sawtooth surfaces shown on the lower surface in FIGS. 10a and 10b , can be smooth and coated (e.g. with an aluminum coating or a dielectric mirror coating) to provide a high level of reflectivity without scattering. Structure 1050 includes a curved face on the left side (as shown) to focus the rays after they pass through the exit surface 1040, thereby providing a mechanism for collimating the uniform light 1008. In a further embodiment, a diffuser can be provided between the solid state light source 1002 and the entrance face 1045 to homogenize the light provided by the solid state light source 1002. In yet a further embodiment, a polarizer can be used between the diffuser and the entrance face 1045 of the backlight 1004 to provide a polarized light source. Because the sawtooth pattern provides smooth reflective surfaces, the polarization state of the light can be preserved from the entrance face 1045 to the exit face 1040. In this embodiment, the light entering the backlight from the solid state light source 1002 passes through the polarizer so that it is polarized with the desired polarization state. If the polarizer is an absorptive linear polarizer, the light of the desired polarization state is transmitted while the light of the other polarization state is absorbed. If the polarizer is a reflective polarizer, the light of the desired polarization state is transmitted into the backlight 1004 while the light of the other polarization state is reflected back into the solid state light source 1002 where it can be recycled as previously described, to increase the efficiency of the polarized light source.

FIG. 11a illustrates a light source 1100 that may be used in association with the upper optics module 202. In embodiments, the light source 1100 may provide light to a backlighting optical system 1004 as described above in connection with FIG. 10. In embodiments, the light source 1100 includes a tristimulus notch filter 1102. The tristimulus notch filter 1102 has narrow band pass filters for three wavelengths, as indicated in FIG. 11c in a transmission graph 1108. The graph shown in FIG. 11b , as 1104 illustrates an output of three different colored LEDs. One can see that the bandwidths of emission are narrow, but they have long tails. The tristimulus notch filter 1102 can be used in connection with such LEDs to provide a light source 1100 that emits narrow filtered wavelengths of light as shown in FIG. 11d as the transmission graph 1110. Wherein the clipping effects of the tristimulus notch filter 1102 can be seen to have cut the tails from the LED emission graph 1104 to provide narrower wavelength bands of light to the upper optical module 202. The light source 1100 can be used in connection with a combiner 602 with a holographic mirror or tristimulus notch mirror to provide narrow bands of light that are reflected toward the wearer's eye with less waste light that does not get reflected by the combiner, thereby improving efficiency and reducing escaping light that can cause faceglow.

FIG. 12a illustrates another light source 1200 that may be used in association with the upper optics module 202. In embodiments, the light source 1200 may provide light to a backlighting optical system 1004 as described above in connection with FIG. 10. In embodiments, the light source 1200 includes a quantum dot cover glass 1202. Where the quantum dots absorb light of a shorter wavelength and emit light of a longer wavelength (FIG. 12b shows an example wherein a UV spectrum 1202 applied to a quantum dot results in the quantum dot emitting a narrow band shown as a PL spectrum 1204) that is dependent on the material makeup and size of the quantum dot. As a result, quantum dots in the quantum dot cover glass 1202 can be tailored to provide one or more bands of narrow bandwidth light (e.g. red, green and blue emissions dependent on the different quantum dots included as illustrated in the graph shown in FIG. 12c where three different quantum dots are used. In embodiments, the LED driver light emits UV light, deep blue or blue light. For sequential illumination of different colors, multiple light sources 1200 would be used where each light source 1200 would include a quantum dot cover glass 1202 with a quantum dot selected to emit at one of the desired colors. The light source 1100 can be used in connection with a combiner 602 with a holographic mirror or tristimulus notch mirror to provide narrow transmission bands of light that are reflected toward the wearer's eye with less waste light that does not get reflected.

Another aspect of the present invention relates to the generation of peripheral image lighting effects for a person wearing a HWC. In embodiments, a solid state lighting system (e.g. LED, OLED, etc), or other lighting system, may be included inside the optical elements of an lower optical module 204. The solid state lighting system may be arranged such that lighting effects outside of a field of view (FOV) of the presented digital content is presented to create an immersive effect for the person wearing the HWC. To this end, the lighting effects may be presented to any portion of the HWC that is visible to the wearer. The solid state lighting system may be digitally controlled by an integrated processor on the HWC. In embodiments, the integrated processor will control the lighting effects in coordination with digital content that is presented within the FOV of the HWC. For example, a movie, picture, game, or other content, may be displayed or playing within the FOV of the HWC. The content may show a bomb blast on the right side of the FOV and at the same moment, the solid state lighting system inside of the upper module optics may flash quickly in concert with the FOV image effect. The effect may not be fast, it may be more persistent to indicate, for example, a general glow or color on one side of the user. The solid state lighting system may be color controlled, with red, green and blue LEDs, for example, such that color control can be coordinated with the digitally presented content within the field of view.

FIG. 13a illustrates optical components of a lower optical module 204 together with an outer lens 1302. FIG. 13a also shows an embodiment including effects LED's 1308 a and 1308 b. FIG. 13a illustrates image light 1312, as described herein elsewhere, directed into the upper optical module where it will reflect off of the combiner element 1304, as described herein elsewhere. The combiner element 1304 in this embodiment is angled towards the wearer's eye at the top of the module and away from the wearer's eye at the bottom of the module, as also illustrated and described in connection with FIG. 8 (e.g. at a 45 degree angle). The image light 1312 provided by an upper optical module 202 (not shown in FIG. 13a ) reflects off of the combiner element 1304 towards the collimating mirror 1310, away from the wearer's eye, as described herein elsewhere. The image light 1312 then reflects and focuses off of the collimating mirror 1304, passes back through the combiner element 1304, and is directed into the wearer's eye. The wearer can also view the surrounding environment through the transparency of the combiner element 1304, collimating mirror 1310, and outer lens 1302 (if it is included). As described herein elsewhere, various surfaces are polarized to create the optical path for the image light and to provide transparency of the elements such that the wearer can view the surrounding environment. The wearer will generally perceive that the image light forms an image in the FOV 1305. In embodiments, the outer lens 1302 may be included. The outer lens 1302 is an outer lens that may or may not be corrective and it may be designed to conceal the lower optical module components in an effort to make the HWC appear to be in a form similar to standard glasses or sunglasses.

In the embodiment illustrated in FIG. 13a , the effects LEDs 1308 a and 1308 b are positioned at the sides of the combiner element 1304 and the outer lens 1302 and/or the collimating mirror 1310. In embodiments, the effects LEDs 1308 a are positioned within the confines defined by the combiner element 1304 and the outer lens 1302 and/or the collimating mirror. The effects LEDs 1308 a and 1308 b are also positioned outside of the FOV 1305. In this arrangement, the effects LEDs 1308 a and 1308 b can provide lighting effects within the lower optical module outside of the FOV 1305. In embodiments the light emitted from the effects LEDs 1308 a and 1308 b may be polarized such that the light passes through the combiner element 1304 toward the wearer's eye and does not pass through the outer lens 1302 and/or the collimating mirror 1310. This arrangement provides peripheral lighting effects to the wearer in a more private setting by not transmitting the lighting effects through the front of the HWC into the surrounding environment. However, in other embodiments, the effects LEDs 1308 a and 1308 b may be unpolarized so the lighting effects provided are made to be purposefully viewable by others in the environment for entertainment such as giving the effect of the wearer's eye glowing in correspondence to the image content being viewed by the wearer.

FIG. 13b illustrates a cross section of the embodiment described in connection with FIG. 13a . As illustrated, the effects LED 1308 a is located in the upper-front area inside of the optical components of the lower optical module. It should be understood that the effects LED 1308 a position in the described embodiments is only illustrative and alternate placements are encompassed by the present invention. Additionally, in embodiments, there may be one or more effects LEDs 1308 a in each of the two sides of HWC to provide peripheral lighting effects near one or both eyes of the wearer.

FIG. 13c illustrates an embodiment where the combiner element 1304 is angled away from the eye at the top and towards the eye at the bottom (e.g. in accordance with the holographic or notch filter embodiments described herein). In this embodiment, the effects LED 1308 a is located on the outer lens 1302 side of the combiner element 1304 to provide a concealed appearance of the lighting effects. As with other embodiments, the effects LED 1308 a of FIG. 13c may include a polarizer such that the emitted light can pass through a polarized element associated with the combiner element 1304 and be blocked by a polarized element associated with the outer lens 1302.

Another aspect of the present invention relates to the mitigation of light escaping from the space between the wearer's face and the HWC itself. Another aspect of the present invention relates to maintaining a controlled lighting environment in proximity to the wearer's eyes. In embodiments, both the maintenance of the lighting environment and the mitigation of light escape are accomplished by including a removable and replaceable flexible shield for the HWC. Wherein the removable and replaceable shield can be provided for one eye or both eyes in correspondence to the use of the displays for each eye. For example, in a night vision application, the display to only one eye could be used for night vision while the display to the other eye is turned off to provide good see-through when moving between areas where visible light is available and dark areas where night vision enhancement is needed.

FIG. 14a illustrates a removable and replaceable flexible eye cover 1402 with an opening 1408 that can be attached and removed quickly from the HWC 102 through the use of magnets. Other attachment methods may be used, but for illustration of the present invention we will focus on a magnet implementation. In embodiments, magnets may be included in the eye cover 1402 and magnets of an opposite polarity may be included (e.g. embedded) in the frame of the HWC 102. The magnets of the two elements would attract quite strongly with the opposite polarity configuration. In another embodiment, one of the elements may have a magnet and the other side may have metal for the attraction. In embodiments, the eye cover 1402 is a flexible elastomeric shield. In embodiments, the eye cover 1402 may be an elastomeric bellows design to accommodate flexibility and more closely align with the wearer's face. FIG. 14b illustrates a removable and replaceable flexible eye cover 1404 that is adapted as a single eye cover. In embodiments, a single eye cover may be used for each side of the HWC to cover both eyes of the wearer. In embodiments, the single eye cover may be used in connection with a HWC that includes only one computer display for one eye. These configurations prevent light that is generated and directed generally towards the wearer's face by covering the space between the wearer's face and the HWC. The opening 1408 allows the wearer to look through the opening 1408 to view the displayed content and the surrounding environment through the front of the HWC. The image light in the lower optical module 204 can be prevented from emitting from the front of the HWC through internal optics polarization schemes, as described herein, for example.

FIG. 14c illustrates another embodiment of a light suppression system. In this embodiment, the eye cover 1410 may be similar to the eye cover 1402, but eye cover 1410 includes a front light shield 1412. The front light shield 1412 may be opaque to prevent light from escaping the front lens of the HWC. In other embodiments, the front light shield 1412 is polarized to prevent light from escaping the front lens. In a polarized arrangement, in embodiments, the internal optical elements of the HWC (e.g. of the lower optical module 204) may polarize light transmitted towards the front of the HWC and the front light shield 1412 may be polarized to prevent the light from transmitting through the front light shield 1412.

In embodiments, an opaque front light shield 1412 may be included and the digital content may include images of the surrounding environment such that the wearer can visualize the surrounding environment. One eye may be presented with night vision environmental imagery and this eye's surrounding environment optical path may be covered using an opaque front light shield 1412. In other embodiments, this arrangement may be associated with both eyes.

Another aspect of the present invention relates to automatically configuring the lighting system(s) used in the HWC 102. In embodiments, the display lighting and/or effects lighting, as described herein, may be controlled in a manner suitable for when an eye cover 1408 is attached or removed from the HWC 102. For example, at night, when the light in the environment is low, the lighting system(s) in the HWC may go into a low light mode to further control any amounts of stray light escaping from the HWC and the areas around the HWC. Covert operations at night, while using night vision or standard vision, may require a solution which prevents as much escaping light as possible so a user may clip on the eye cover(s) 1408 and then the HWC may go into a low light mode. The low light mode may, in some embodiments, only go into a low light mode when the eye cover 1408 is attached if the HWC identifies that the environment is in low light conditions (e.g. through environment light level sensor detection). In embodiments, the low light level may be determined to be at an intermediate point between full and low light dependent on environmental conditions.

Another aspect of the present invention relates to automatically controlling the type of content displayed in the HWC when eye covers 1408 are attached or removed from the HWC. In embodiments, when the eye cover(s) 1408 is attached to the HWC, the displayed content may be restricted in amount or in color amounts. For example, the display(s) may go into a simple content delivery mode to restrict the amount of information displayed. This may be done to reduce the amount of light produced by the display(s). In an embodiment, the display(s) may change from color displays to monochrome displays to reduce the amount of light produced. In an embodiment, the monochrome lighting may be red to limit the impact on the wearer's eyes to maintain an ability to see better in the dark.

Referring to FIG. 15, we now turn to describe a particular external user interface 104, referred to generally as a pen 1500. The pen 1500 is a specially designed external user interface 104 and can operate as a user interface, such as to many different styles of HWC 102. The pen 1500 generally follows the form of a conventional pen, which is a familiar user handled device and creates an intuitive physical interface for many of the operations to be carried out in the HWC system 100. The pen 1500 may be one of several user interfaces 104 used in connection with controlling operations within the HWC system 100. For example, the HWC 102 may watch for and interpret hand gestures 116 as control signals, where the pen 1500 may also be used as a user interface with the same HWC 102. Similarly, a remote keyboard may be used as an external user interface 104 in concert with the pen 1500. The combination of user interfaces or the use of just one control system generally depends on the operation(s) being executed in the HWC's system 100.

While the pen 1500 may follow the general form of a conventional pen, it contains numerous technologies that enable it to function as an external user interface 104. FIG. 15 illustrates technologies comprised in the pen 1500. As can be seen, the pen 1500 may include a camera 1508, which is arranged to view through lens 1502. The camera may then be focused, such as through lens 1502, to image a surface upon which a user is writing or making other movements to interact with the HWC 102. There are situations where the pen 1500 will also have an ink, graphite, or other system such that what is being written can be seen on the writing surface. There are other situations where the pen 1500 does not have such a physical writing system so there is no deposit on the writing surface, where the pen would only be communicating data or commands to the HWC 102. The lens configuration is described in greater detail herein. The function of the camera is to capture information from an unstructured writing surface such that pen strokes can be interpreted as intended by the user. To assist in the predication of the intended stroke path, the pen 1500 may include a sensor, such as an IMU 1512. Of course, the IMU could be included in the pen 1500 in its separate parts (e.g. gyro, accelerometer, etc.) or an IMU could be included as a single unit. In this instance, the IMU 1512 is used to measure and predict the motion of the pen 1500. In turn, the integrated microprocessor 1510 would take the IMU information and camera information as inputs and process the information to form a prediction of the pen tip movement.

The pen 1500 may also include a pressure monitoring system 1504, such as to measure the pressure exerted on the lens 1502. As will be described in greater detail herein, the pressure measurement can be used to predict the user's intention for changing the weight of a line, type of a line, type of brush, click, double click, and the like. In embodiments, the pressure sensor may be constructed using any force or pressure measurement sensor located behind the lens 1502, including for example, a resistive sensor, a current sensor, a capacitive sensor, a voltage sensor such as a piezoelectric sensor, and the like.

The pen 1500 may also include a communications module 1518, such as for bi-directional communication with the HWC 102. In embodiments, the communications module 1518 may be a short distance communication module (e.g. Bluetooth). The communications module 1518 may be security matched to the HWC 102. The communications module 1518 may be arranged to communicate data and commands to and from the microprocessor 1510 of the pen 1500. The microprocessor 1510 may be programmed to interpret data generated from the camera 1508, IMU 1512, and pressure sensor 1504, and the like, and then pass a command onto the HWC 102 through the communications module 1518, for example. In another embodiment, the data collected from any of the input sources (e.g. camera 1508, IMU 1512, pressure sensor 1504) by the microprocessor may be communicated by the communication module 1518 to the HWC 102, and the HWC 102 may perform data processing and prediction of the user's intention when using the pen 1500. In yet another embodiment, the data may be further passed on through a network 110 to a remote device 112, such as a server, for the data processing and prediction. The commands may then be communicated back to the HWC 102 for execution (e.g. display writing in the glasses display, make a selection within the UI of the glasses display, control a remote external device 112, control a local external device 108), and the like. The pen may also include memory 1514 for long or short term uses.

The pen 1500 may also include a number of physical user interfaces, such as quick launch buttons 1522, a touch sensor 1520, and the like. The quick launch buttons 1522 may be adapted to provide the user with a fast way of jumping to a software application in the HWC system 100. For example, the user may be a frequent user of communication software packages (e.g. email, text, Twitter, Instagram, Facebook, Google+, and the like), and the user may program a quick launch button 1522 to command the HWC 102 to launch an application. The pen 1500 may be provided with several quick launch buttons 1522, which may be user programmable or factory programmable. The quick launch button 1522 may be programmed to perform an operation. For example, one of the buttons may be programmed to clear the digital display of the HWC 102. This would create a fast way for the user to clear the screens on the HWC 102 for any reason, such as for example to better view the environment. The quick launch button functionality will be discussed in further detail below. The touch sensor 1520 may be used to take gesture style input from the user. For example, the user may be able to take a single finger and run it across the touch sensor 1520 to affect a page scroll.

The pen 1500 may also include a laser pointer 1524. The laser pointer 1524 may be coordinated with the IMU 1512 to coordinate gestures and laser pointing. For example, a user may use the laser 1524 in a presentation to help with guiding the audience with the interpretation of graphics and the IMU 1512 may, either simultaneously or when the laser 1524 is off, interpret the user's gestures as commands or data input.

FIGS. 16A-C illustrate several embodiments of lens and camera arrangements 1600 for the pen 1500. One aspect relates to maintaining a constant distance between the camera and the writing surface to enable the writing surface to be kept in focus for better tracking of movements of the pen 1500 over the writing surface. Another aspect relates to maintaining an angled surface following the circumference of the writing tip of the pen 1500 such that the pen 1500 can be rolled or partially rolled in the user's hand to create the feel and freedom of a conventional writing instrument.

FIG. 16A illustrates an embodiment of the writing lens end of the pen 1500. The configuration includes a ball lens 1604, a camera or image capture surface 1602, and a domed cover lens 1608. In this arrangement, the camera views the writing surface through the ball lens 1604 and dome cover lens 1608. The ball lens 1604 causes the camera to focus such that the camera views the writing surface when the pen 1500 is held in the hand in a natural writing position, such as with the pen 1500 in contact with a writing surface. In embodiments, the ball lens 1604 should be separated from the writing surface to obtain the highest resolution of the writing surface at the camera 1602. In embodiments, the ball lens 1604 is separated by approximately 1 to 3 mm. In this configuration, the domed cover lens 1608 provides a surface that can keep the ball lens 1604 separated from the writing surface at a constant distance, such as substantially independent of the angle used to write on the writing surface. For instance, in embodiments the field of view of the camera in this arrangement would be approximately 60 degrees.

The domed cover lens, or other lens 1608 used to physically interact with the writing surface, will be transparent or transmissive within the active bandwidth of the camera 1602. In embodiments, the domed cover lens 1608 may be spherical or other shape and comprised of glass, plastic, sapphire, diamond, and the like. In other embodiments where low resolution imaging of the surface is acceptable. The pen 1500 can omit the domed cover lens 1608 and the ball lens 1604 can be in direct contact with the surface.

FIG. 16B illustrates another structure where the construction is somewhat similar to that described in connection with FIG. 16A; however this embodiment does not use a dome cover lens 1608, but instead uses a spacer 1610 to maintain a predictable distance between the ball lens 1604 and the writing surface, wherein the spacer may be spherical, cylindrical, tubular or other shape that provides spacing while allowing for an image to be obtained by the camera 1602 through the lens 1604. In a preferred embodiment, the spacer 1610 is transparent. In addition, while the spacer 1610 is shown as spherical, other shapes such as an oval, doughnut shape, half sphere, cone, cylinder or other form may be used.

FIG. 16C illustrates yet another embodiment, where the structure includes a post 1614, such as running through the center of the lensed end of the pen 1500. The post 1614 may be an ink deposition system (e.g. ink cartridge), graphite deposition system (e.g. graphite holder), or a dummy post whose purpose is mainly only that of alignment. The selection of the post type is dependent on the pen's use. For instance, in the event the user wants to use the pen 1500 as a conventional ink depositing pen as well as a fully functional external user interface 104, the ink system post would be the best selection. If there is no need for the ‘writing’ to be visible on the writing surface, the selection would be the dummy post. The embodiment of FIG. 16C includes camera(s) 1602 and an associated lens 1612, where the camera 1602 and lens 1612 are positioned to capture the writing surface without substantial interference from the post 1614. In embodiments, the pen 1500 may include multiple cameras 1602 and lenses 1612 such that more or all of the circumference of the tip 1614 can be used as an input system. In an embodiment, the pen 1500 includes a contoured grip that keeps the pen aligned in the user's hand so that the camera 1602 and lens 1612 remains pointed at the surface.

Another aspect of the pen 1500 relates to sensing the force applied by the user to the writing surface with the pen 1500. The force measurement may be used in a number of ways. For example, the force measurement may be used as a discrete value, or discontinuous event tracking, and compared against a threshold in a process to determine a user's intent. The user may want the force interpreted as a ‘click’ in the selection of an object, for instance. The user may intend multiple force exertions interpreted as multiple clicks. There may be times when the user holds the pen 1500 in a certain position or holds a certain portion of the pen 1500 (e.g. a button or touch pad) while clicking to affect a certain operation (e.g. a ‘right click’). In embodiments, the force measurement may be used to track force and force trends. The force trends may be tracked and compared to threshold limits, for example. There may be one such threshold limit, multiple limits, groups of related limits, and the like. For example, when the force measurement indicates a fairly constant force that generally falls within a range of related threshold values, the microprocessor 1510 may interpret the force trend as an indication that the user desires to maintain the current writing style, writing tip type, line weight, brush type, and the like. In the event that the force trend appears to have gone outside of a set of threshold values intentionally, the microprocessor may interpret the action as an indication that the user wants to change the current writing style, writing tip type, line weight, brush type, and the like. Once the microprocessor has made a determination of the user's intent, a change in the current writing style, writing tip type, line weight, brush type, and the like may be executed. In embodiments, the change may be noted to the user (e.g. in a display of the HWC 102), and the user may be presented with an opportunity to accept the change.

FIG. 17A illustrates an embodiment of a force sensing surface tip 1700 of a pen 1500. The force sensing surface tip 1700 comprises a surface connection tip 1702 (e.g. a lens as described herein elsewhere) in connection with a force or pressure monitoring system 1504. As a user uses the pen 1500 to write on a surface or simulate writing on a surface the force monitoring system 1504 measures the force or pressure the user applies to the writing surface and the force monitoring system communicates data to the microprocessor 1510 for processing. In this configuration, the microprocessor 1510 receives force data from the force monitoring system 1504 and processes the data to make predictions of the user's intent in applying the particular force that is currently being applied. In embodiments, the processing may be provided at a location other than on the pen (e.g. at a server in the HWC system 100, on the HWC 102). For clarity, when reference is made herein to processing information on the microprocessor 1510, the processing of information contemplates processing the information at a location other than on the pen. The microprocessor 1510 may be programmed with force threshold(s), force signature(s), force signature library and/or other characteristics intended to guide an inference program in determining the user's intentions based on the measured force or pressure. The microprocessor 1510 may be further programmed to make inferences from the force measurements as to whether the user has attempted to initiate a discrete action (e.g. a user interface selection ‘click’) or is performing a constant action (e.g. writing within a particular writing style). The inferencing process is important as it causes the pen 1500 to act as an intuitive external user interface 104.

FIG. 17B illustrates a force 1708 versus time 1710 trend chart with a single threshold 1718. The threshold 1718 may be set at a level that indicates a discrete force exertion indicative of a user's desire to cause an action (e.g. select an object in a GUI). Event 1712, for example, may be interpreted as a click or selection command because the force quickly increased from below the threshold 1718 to above the threshold 1718. The event 1714 may be interpreted as a double click because the force quickly increased above the threshold 1718, decreased below the threshold 1718 and then essentially repeated quickly. The user may also cause the force to go above the threshold 1718 and hold for a period indicating that the user is intending to select an object in the GUI (e.g. a GUI presented in the display of the HWC 102) and ‘hold’ for a further operation (e.g. moving the object).

While a threshold value may be used to assist in the interpretation of the user's intention, a signature force event trend may also be used. The threshold and signature may be used in combination or either method may be used alone. For example, a single-click signature may be represented by a certain force trend signature or set of signatures. The single-click signature(s) may require that the trend meet a criteria of a rise time between x any y values, a hold time of between a and b values and a fall time of between c and d values, for example. Signatures may be stored for a variety of functions such as click, double click, right click, hold, move, etc. The microprocessor 1510 may compare the real-time force or pressure tracking against the signatures from a signature library to make a decision and issue a command to the software application executing in the GUI.

FIG. 17C illustrates a force 1708 versus time 1710 trend chart with multiple thresholds 1718. By way of example, the force trend is plotted on the chart with several pen force or pressure events. As noted, there are both presumably intentional events 1720 and presumably non-intentional events 1722. The two thresholds 1718 of FIG. 4C create three zones of force: a lower, middle and higher range. The beginning of the trend indicates that the user is placing a lower zone amount of force. This may mean that the user is writing with a given line weight and does not intend to change the weight, the user is writing. Then the trend shows a significant increase 1720 in force into the middle force range. This force change appears, from the trend to have been sudden and thereafter it is sustained. The microprocessor 1510 may interpret this as an intentional change and as a result change the operation in accordance with preset rules (e.g. change line width, increase line weight, etc.). The trend then continues with a second apparently intentional event 1720 into the higher-force range. During the performance in the higher-force range, the force dips below the upper threshold 1718. This may indicate an unintentional force change and the microprocessor may detect the change in range however not affect a change in the operations being coordinated by the pen 1500. As indicated above, the trend analysis may be done with thresholds and/or signatures.

Generally, in the present disclosure, instrument stroke parameter changes may be referred to as a change in line type, line weight, tip type, brush type, brush width, brush pressure, color, and other forms of writing, coloring, painting, and the like.

Another aspect of the pen 1500 relates to selecting an operating mode for the pen 1500 dependent on contextual information and/or selection interface(s). The pen 1500 may have several operating modes. For instance, the pen 1500 may have a writing mode where the user interface(s) of the pen 1500 (e.g. the writing surface end, quick launch buttons 1522, touch sensor 1520, motion based gesture, and the like) is optimized or selected for tasks associated with writing. As another example, the pen 1500 may have a wand mode where the user interface(s) of the pen is optimized or selected for tasks associated with software or device control (e.g. the HWC 102, external local device, remote device 112, and the like). The pen 1500, by way of another example, may have a presentation mode where the user interface(s) is optimized or selected to assist a user with giving a presentation (e.g. pointing with the laser pointer 1524 while using the button(s) 1522 and/or gestures to control the presentation or applications relating to the presentation). The pen may, for example, have a mode that is optimized or selected for a particular device that a user is attempting to control. The pen 1500 may have a number of other modes and an aspect of the present invention relates to selecting such modes.

FIG. 18A illustrates an automatic user interface(s) mode selection based on contextual information. The microprocessor 1510 may be programmed with IMU thresholds 1814 and 1812. The thresholds 1814 and 1812 may be used as indications of upper and lower bounds of an angle 1804 and 1802 of the pen 1500 for certain expected positions during certain predicted modes. When the microprocessor 1510 determines that the pen 1500 is being held or otherwise positioned within angles 1802 corresponding to writing thresholds 1814, for example, the microprocessor 1510 may then institute a writing mode for the pen's user interfaces. Similarly, if the microprocessor 1510 determines (e.g. through the IMU 1512) that the pen is being held at an angle 1804 that falls between the predetermined wand thresholds 1812, the microprocessor may institute a wand mode for the pen's user interface. Both of these examples may be referred to as context based user interface mode selection as the mode selection is based on contextual information (e.g. position) collected automatically and then used through an automatic evaluation process to automatically select the pen's user interface(s) mode.

As with other examples presented herein, the microprocessor 1510 may monitor the contextual trend (e.g. the angle of the pen over time) in an effort to decide whether to stay in a mode or change modes. For example, through signatures, thresholds, trend analysis, and the like, the microprocessor may determine that a change is an unintentional change and therefore no user interface mode change is desired.

FIG. 18B illustrates an automatic user interface(s) mode selection based on contextual information. In this example, the pen 1500 is monitoring (e.g. through its microprocessor) whether or not the camera at the writing surface end 1508 is imaging a writing surface in close proximity to the writing surface end of the pen 1500. If the pen 1500 determines that a writing surface is within a predetermined relatively short distance, the pen 1500 may decide that a writing surface is present 1820 and the pen may go into a writing mode user interface(s) mode. In the event that the pen 1500 does not detect a relatively close writing surface 1822, the pen may predict that the pen is not currently being used to as a writing instrument and the pen may go into a non-writing user interface(s) mode.

FIG. 18C illustrates a manual user interface(s) mode selection. The user interface(s) mode may be selected based on a twist of a section 1824 of the pen 1500 housing, clicking an end button 1828, pressing a quick launch button 1522, interacting with touch sensor 1520, detecting a predetermined action at the pressure monitoring system (e.g. a click), detecting a gesture (e.g. detected by the IMU), etc. The manual mode selection may involve selecting an item in a GUI associated with the pen 1500 (e.g. an image presented in the display of HWC 102).

In embodiments, a confirmation selection may be presented to the user in the event a mode is going to change. The presentation may be physical (e.g. a vibration in the pen 1500), through a GUI, through a light indicator, etc.

FIG. 19 illustrates a couple pen use-scenarios 1900 and 1901. There are many use scenarios and we have presented a couple in connection with FIG. 19 as a way of illustrating use scenarios to further the understanding of the reader. As such, the use-scenarios should be considered illustrative and non-limiting.

Use scenario 1900 is a writing scenario where the pen 1500 is used as a writing instrument. In this example, quick launch button 122A is pressed to launch a note application 1910 in the GUI 1908 of the HWC 102 display 1904. Once the quick launch button 122A is pressed, the HWC 102 launches the note program 1910 and puts the pen into a writing mode. The user uses the pen 1500 to scribe symbols 1902 on a writing surface, the pen records the scribing and transmits the scribing to the HWC 102 where symbols representing the scribing are displayed 1912 within the note application 1910.

Use scenario 1901 is a gesture scenario where the pen 1500 is used as a gesture capture and command device. In this example, the quick launch button 122B is activated and the pen 1500 activates a wand mode such that an application launched on the HWC 102 can be controlled. Here, the user sees an application chooser 1918 in the display(s) of the HWC 102 where different software applications can be chosen by the user. The user gestures (e.g. swipes, spins, turns, etc.) with the pen to cause the application chooser 1918 to move from application to application. Once the correct application is identified (e.g. highlighted) in the chooser 1918, the user may gesture or click or otherwise interact with the pen 1500 such that the identified application is selected and launched. Once an application is launched, the wand mode may be used to scroll, rotate, change applications, select items, initiate processes, and the like, for example.

In an embodiment, the quick launch button 122A may be activated and the HWC 102 may launch an application chooser presenting to the user a set of applications. For example, the quick launch button may launch a chooser to show all communication programs (e.g. SMS, Twitter, Instagram, Facebook, email, etc.) available for selection such that the user can select the program the user wants and then go into a writing mode. By way of further example, the launcher may bring up selections for various other groups that are related or categorized as generally being selected at a given time (e.g. Microsoft Office products, communication products, productivity products, note products, organizational products, and the like)

FIG. 20 illustrates yet another embodiment of the present invention. FIG. 2000 illustrates a watchband clip on controller 2000. The watchband clip on controller may be a controller used to control the HWC 102 or devices in the HWC system 100. The watchband clip on controller 2000 has a fastener 2018 (e.g. rotatable clip) that is mechanically adapted to attach to a watchband, as illustrated at 2004.

The watchband controller 2000 may have quick launch interfaces 2008 (e.g. to launch applications and choosers as described herein), a touch pad 2014 (e.g. to be used as a touch style mouse for GUI control in a HWC 102 display) and a display 2012. The clip 2018 may be adapted to fit a wide range of watchbands so it can be used in connection with a watch that is independently selected for its function. The clip, in embodiments, is rotatable such that a user can position it in a desirable manner. In embodiments the clip may be a flexible strap. In embodiments, the flexible strap may be adapted to be stretched to attach to a hand, wrist, finger, device, weapon, and the like.

In embodiments, the watchband controller may be configured as a removable and replaceable watchband. For example, the controller may be incorporated into a band with a certain width, segment spacing's, etc. such that the watchband, with its incorporated controller, can be attached to a watch body. The attachment, in embodiments, may be mechanically adapted to attach with a pin upon which the watchband rotates. In embodiments, the watchband controller may be electrically connected to the watch and/or watch body such that the watch, watch body and/or the watchband controller can communicate data between them.

The watchband controller may have 3-axis motion monitoring (e.g. through an IMU, accelerometers, magnetometers, gyroscopes, etc.) to capture user motion. The user motion may then be interpreted for gesture control.

In embodiments, the watchband controller may comprise fitness sensors and a fitness computer. The sensors may track heart rate, calories burned, strides, distance covered, and the like. The data may then be compared against performance goals and/or standards for user feedback.

Another aspect of the present invention relates to visual display techniques relating to micro Doppler (“mD”) target tracking signatures (“mD signatures”). mD is a radar technique that uses a series of angle dependent electromagnetic pulses that are broadcast into an environment and return pulses are captured. Changes between the broadcast pulse and return pulse are indicative of changes in the shape, distance and angular location of objects or targets in the environment. These changes provide signals that can be used to track a target and identify the target through the mD signature. Each target or target type has a unique mD signature. Shifts in the radar pattern can be analyzed in the time domain and frequency domain based on mD techniques to derive information about the types of targets present (e.g. whether people are present), the motion of the targets and the relative angular location of the targets and the distance to the targets. By selecting a frequency used for the mD pulse relative to known objects in the environment, the pulse can penetrate the known objects to enable information about targets to be gathered even when the targets are visually blocked by the known objects. For example, pulse frequencies can be used that will penetrate concrete buildings to enable people to be identified inside the building. Multiple pulse frequencies can be used as well in the mD radar to enable different types of information to be gathered about the objects in the environment. In addition, the mD radar information can be combined with other information such as distance measurements or images captured of the environment that are analyzed jointly to provide improved object identification and improved target identification and tracking. In embodiments, the analysis can be performed on the HWC or the information can be transmitted to a remote network for analysis and results transmitted back to the HWC. Distance measurements can be provided by laser range finding, structured lighting, stereoscopic depth maps or sonar measurements. Images of the environment can be captured using one or more cameras capable of capturing images from visible, ultraviolet or infrared light. The mD radar can be attached to the HWC, located adjacently (e.g. in a vehicle) and associated wirelessly with the HWC or located remotely. Maps or other previously determined information about the environment can also be used in the analysis of the mD radar information. Embodiments of the present invention relate to visualizing the mD signatures in useful ways.

FIG. 21 illustrates a FOV 2102 of a HWC 102 from a wearer's perspective. The wearer, as described herein elsewhere, has a see-through FOV 2102 wherein the wearer views adjacent surroundings, such as the buildings illustrated in FIG. 21. The wearer, as described herein elsewhere, can also see displayed digital content presented within a portion of the FOV 2102. The embodiment illustrated in FIG. 21 is indicating that the wearer can see the buildings and other surrounding elements in the environment and digital content representing traces, or travel paths, of bullets being fired by different people in the area. The surroundings are viewed through the transparency of the FOV 2102. The traces are presented via the digital computer display, as described herein elsewhere. In embodiments, the trace presented is based on a mD signature that is collected and communicated to the HWC in real time. The mD radar itself may be on or near the wearer of the HWC 102 or it may be located remote from the wearer. In embodiments, the mD radar scans the area, tracks and identifies targets, such as bullets, and communicates traces, based on locations, to the HWC 102.

There are several traces 2108 and 2104 presented to the wearer in the embodiment illustrated in FIG. 21. The traces communicated from the mD radar may be associated with GPS locations and the GPS locations may be associated with objects in the environment, such as people, buildings, vehicles, etc, both in latitude and longitude perspective and an elevation perspective. The locations may be used as markers for the HWC such that the traces, as presented in the FOV, can be associated, or fixed in space relative to the markers. For example, if the friendly fire trace 2108 is determined, by the mD radar, to have originated from the upper right window of the building on the left, as illustrated in FIG. 21, then a virtual marker may be set on or near the window. When the HWC views, through its camera or other sensor, for example, the building's window, the trace may then virtually anchor with the virtual marker on the window. Similarly, a marker may be set near the termination position or other flight position of the friendly fire trace 2108, such as the upper left window of the center building on the right, as illustrated in FIG. 21. This technique fixes in space the trace such that the trace appears fixed to the environmental positions independent of where the wearer is looking. So, for example, as the wearer's head turns, the trace appears fixed to the marked locations.

In embodiments, certain user positions may be known and thus identified in the FOV. For example, the shooter of the friendly fire trace 2108 may be from a known friendly combatant and as such his location may be known. The position may be known based on his GPS location based on a mobile communication system on him, such as another HWC 102. In other embodiments, the friendly combatant may be marked by another friendly. For example, if the friendly position in the environment is known through visual contact or communicated information, a wearer of the HWC 102 may use a gesture or external user interface 104 to mark the location. If a friendly combatant location is known the originating position of the friendly fire trace 2108 may be color coded or otherwise distinguished from unidentified traces on the displayed digital content. Similarly, enemy fire traces 2104 may be color coded or otherwise distinguished on the displayed digital content. In embodiments, there may be an additional distinguished appearance on the displayed digital content for unknown traces.

In addition to situationally associated trace appearance, the trace colors or appearance may be different from the originating position to the terminating position. This path appearance change may be based on the mD signature. The mD signature may indicate that the bullet, for example, is slowing as it propagates and this slowing pattern may be reflected in the FOV 2102 as a color or pattern change. This can create an intuitive understanding of wear the shooter is located. For example, the originating color may be red, indicative of high speed, and it may change over the course of the trace to yellow, indicative of a slowing trace. This pattern changing may also be different for a friendly, enemy and unknown combatant. The enemy may go blue to green for a friendly trace, for example.

FIG. 21 illustrates an embodiment where the user sees the environment through the FOV and may also see color coded traces, which are dependent on bullet speed and combatant type, where the traces are fixed in environmental positions independent on the wearer's perspective. Other information, such as distance, range, range rings, time of day, date, engagement type (e.g. hold, stop firing, back away, etc.) may also be displayed in the FOV.

Another aspect of the present invention relates to mD radar techniques that trace and identify targets through other objects, such as walls (referred to generally as through wall mD), and visualization techniques related therewith. FIG. 22 illustrates a through wall mD visualization technique according to the principles of the present invention. As described herein elsewhere, the mD radar scanning the environment may be local or remote from the wearer of a HWC 102. The mD radar may identify a target (e.g. a person) that is visible 2204 and then track the target as he goes behind a wall 2208. The tracking may then be presented to the wearer of a HWC 102 such that digital content reflective of the target and the target's movement, even behind the wall, is presented in the FOV 2202 of the HWC 102. In embodiments, the target, when out of visible sight, may be represented by an avatar in the FOV to provide the wearer with imagery representing the target.

mD target recognition methods can identify the identity of a target based on the vibrations and other small movements of the target. This can provide a personal signature for the target. In the case of humans, this may result in a personal identification of a target that has been previously characterized. The cardio, heartbeat, lung expansion and other small movements within the body may be unique to a person and if those attributes are pre-identified they may be matched in real time to provide a personal identification of a person in the FOV 2202. The person's mD signatures may be determined based on the position of the person. For example, the database of personal mD signature attributes may include mD signatures for a person standing, sitting, laying down, running, walking, jumping, etc. This may improve the accuracy of the personal data match when a target is tracked through mD signature techniques in the field. In the event a person is personally identified, a specific indication of the person's identity may be presented in the FOV 2202. The indication may be a color, shape, shade, name, indication of the type of person (e.g. enemy, friendly, etc.), etc. to provide the wearer with intuitive real time information about the person being tracked. This may be very useful in a situation where there is more than one person in an area of the person being tracked. If just one person in the area is personally identified, that person or the avatar of that person can be presented differently than other people in the area.

FIG. 23 illustrates an mD scanned environment 2300. An mD radar may scan an environment in an attempt to identify objects in the environment. In this embodiment, the mD scanned environment reveals two vehicles 2302 a and 2302 b, en enemy combatant 2309, two friendly combatants 2308 a and 2308 b and a shottrace 2318. Each of these objects may be personally identified or type identified. For example, the vehicles 2302 a and 2302 b may be identified through the mD signatures as a tank and heavy truck. The enemy combatant 2309 may be identified as a type (e.g. enemy combatant) or more personally (e.g. by name). The friendly combatants may be identified as a type (e.g. friendly combatant) or more personally (e.g. by name). The shot trace 2318 may be characterized by type of projectile or weapon type for the projectile, for example.

FIG. 23a illustrates two separate HWC 102 FOV display techniques according to the principles of the present invention. FOV 2312 illustrates a map view 2310 where the mD scanned environment is presented. Here, the wearer has a perspective on the mapped area so he can understand all tracked targets in the area. This allows the wearer to traverse the area with knowledge of the targets. FOV 2312 illustrates a heads-up view to provide the wearer with an augmented reality style view of the environment that is in proximity of the wearer.

An aspect of the present invention relates to suppression of extraneous or stray light. As discussed herein elsewhere, eyeglow and faceglow are two such artifacts that develop from such light. Eyeglow and faceglow can be caused by image light escaping from the optics module. The escaping light is then visible, particularly in dark environments when the user is viewing bright displayed images with the HWC. Light that escapes through the front of the HWC is visible as eyeglow as it that light that is visible in the region of the user's eyes. Eyeglow can appear in the form of a small version of the displayed image that the user is viewing. Light that escapes from the bottom of the HWC shines onto the user's face, cheek or chest so that these portions of the user appear to glow. Eyeglow and faceglow can both increase the visibility of the user and highlight the use of the HWC, which may be viewed negatively by the user. As such, reducing eyeglow and faceglow is advantageous. In combat situations (e.g. the mD trace presentation scenarios described herein) and certain gaming situations, the suppression of extraneous or stray light is very important.

The disclosure relating to FIG. 6 shows an example where a portion of the image light passes through the combiner 602 such that the light shines onto the user's face, thereby illuminating a portion of the user's face in what is generally referred to herein as faceglow. Faceglow be caused by any portion of light from the HWC that illuminates the user's face.

An example of the source for the faceglow light can come from wide cone angle light associated with the image light incident onto the combiner 602. Where the combiner can include a holographic mirror or a notch mirror in which the narrow bands of high reflectivity are matched to wavelengths of light by the light source. The wide cone angle associated with the image light corresponds with the field of view provided by the HWC. Typically the reflectivity of holographic mirrors and notch mirrors is reduced as the cone angle of the incident light is increased above 8 degrees. As a result, for a field of view of 30 degrees, substantial image light can pass through the combiner and cause faceglow.

FIG. 24 shows an illustration of a light trap 2410 for the faceglow light. In this embodiment, an extension of the outer shield lens of the HWC is coated with a light absorbing material in the region where the converging light responsible for faceglow is absorbed in a light trap 2410. The light absorbing material can be black or it can be a filter designed to absorb only the specific wavelengths of light provided by the light source(s) in the HWC. In addition, the surface of the light trap 2410 may be textured or fibrous to further improve the absorption.

FIG. 25 illustrates an optical system for a HWC that includes an outer absorptive polarizer 2520 to block the faceglow light. In this embodiment, the image light is polarized and as a result the light responsible for faceglow is similarly polarized. The absorptive polarizer is oriented with a transmission axis such that the faceglow light is absorbed and not transmitted. In this case, the rest of the imaging system in the HWC may not require polarized image light and the image light may be polarized at any point before the combiner. In embodiments, the transmission axis of the absorptive polarizer 2520 is oriented vertically so that external glare from water (S polarized light) is absorbed and correspondingly, the polarization of the image light is selected to be horizontal (S polarization). Consequently, image light that passes through the combiner 602 and is then incident onto the absorptive polarizer 2520, is absorbed. In FIG. 25 the absorptive polarizer 2520 is shown outside the shield lens, alternatively the absorptive polarizer 2520 can be located inside the shield lens.

FIG. 26 illustrates an optical system for a HWC that includes a film with an absorptive notch filter 2620. In this case, the absorptive notch filter absorbs narrow bands of light that are selected to match the light provided by the optical system's light source. As a result, the absorptive notch filter is opaque with respect to the faceglow light and is transparent to the remainder of the wavelengths included in the visible spectrum so that the user has a clear view of the surrounding environment. A triple notch filter suitable for this approach is available from Iridian Spectral Technologies, Ottawa, ON: http://www.iiphotonics.com/cdv2/Iridian-Interference%20Filters/New%20filters/Triple%20Notch%20Filter.pdf

In embodiments, the combiner 602 may include a notch mirror coating to reflect the wavelengths of light in the image light and a notch filter 2620 can be selected in correspondence to the wavelengths of light provided by the light source and the narrow bands of high reflectivity provided by the notch mirror. In this way, image light that is not reflected by the notch mirror is absorbed by the notch filter 2620. In embodiments of the invention the light source can provide one narrow band of light for a monochrome imaging or three narrow bands of light for full color imaging. The notch mirror and associated notch filter would then each provide one narrow band or three narrow bands of high reflectivity and absorption respectively.

FIG. 27 includes a microlouver film 2750 to block the faceglow light. Microlouver film is sold by 3M as ALCF-P, for example and is typically used as a privacy filter for computer. See http://multimedia3 m.com/mws/mediawebserver?mwsld=SSSSSuH8gc7nZxtUoY_xlY_eevUqel7 zHvTSevTSeSSSSSS--&fn=ALCF-P_ABR2_Control_Film_DS.pdf. The microlouver film transmits light within a somewhat narrow angle (e.g. 30 degrees of normal and absorbs light beyond 30 degrees of normal). In FIG. 27, the microlouver film 2750 is positioned such that the faceglow light 2758 is incident beyond 30 degrees from normal while the see-through light 2755 is incident within 30 degrees of normal to the microlouver film 2750. As such, the faceglow light 2758 is absorbed by the microlouver film and the see-through light 2755 is transmitted so that the user has a bright see-through view of the surrounding environment.

We now turn back to a description of eye imaging technologies. Aspects of the present invention relate to various methods of imaging the eye of a person wearing the HWC 102. In embodiments, technologies for imaging the eye using an optical path involving the “off” state and “no power” state, which is described in detail below, are described. In embodiments, technologies for imaging the eye with optical configurations that do not involve reflecting the eye image off of DLP mirrors is described. In embodiments, unstructured light, structured light, or controlled lighting conditions, are used to predict the eye's position based on the light reflected off of the front of the wearer's eye. In embodiments, a reflection of a presented digital content image is captured as it reflects off of the wearer's eye and the reflected image may be processed to determine the quality (e.g. sharpness) of the image presented. In embodiments, the image may then be adjusted (e.g. focused differently) to increase the quality of the image presented based on the image reflection.

FIGS. 28a, 28b and 28c show illustrations of the various positions of the DLP mirrors. FIG. 28a shows the DLP mirrors in the “on” state 2815. With the mirror in the “on” state 2815, illumination light 2810 is reflected along an optical axis 2820 that extends into the lower optical module 204. FIG. 28b shows the DLP mirrors in the “off” state 2825. With the mirror in the “off” state 2825, illumination light 2810 is reflected along an optical axis 2830 that is substantially to the side of optical axis 2820 so that the “off” state light is directed toward a dark light trap as has been described herein elsewhere. FIG. 28c shows the DLP mirrors in a third position, which occurs when no power is applied to the DLP. This “no power” state differs from the “on” and “off” states in that the mirror edges are not in contact with the substrate and as such are less accurately positioned. FIG. 28c shows all of the DLP mirrors in the “no power” state 2835. The “no power” state is achieved by simultaneously setting the voltage to zero for the “on” contact and “off” contact for a DLP mirror, as a result, the mirror returns to a no stress position where the DLP mirror is in the plane of the DLP platform as shown in FIG. 28c . Although not normally done, it is also possible to apply the “no power” state to individual DLP mirrors. When the DLP mirrors are in the “no power” state they do not contribute image content. Instead, as shown in FIG. 28c , when the DLP mirrors are in the “no power” state, the illumination light 2810 is reflected along an optical axis 2840 that is between the optical axes 2820 and 2830 that are respectively associated with the “on” and “off” states and as such this light doesn't contribute to the displayed image as a bright or dark pixel. This light can however contribute scattered light into the lower optical module 204 and as a result the displayed image contrast can be reduced or artifacts can be created in the image that detract from the image content. Consequently, it is generally desirable, in embodiments, to limit the time associated with the “no power” state to times when images are not displayed or to reduce the time associated with having DLP mirrors in the “no power” state so that the effect of the scattered light is reduced.

FIG. 29 shows an embodiment of the invention that can be used for displaying digital content images to a wearer of the HWC 102 and capturing images of the wearer's eye. In this embodiment, light from the eye 2971 passes back through the optics in the lower module 204, the solid corrective wedge 2966, at least a portion of the light passes through the partially reflective layer 2960, the solid illumination wedge 2964 and is reflected by a plurality of DLP mirrors on the DLP 2955 that are in the “no power” state. The reflected light then passes back through the illumination wedge 2964 and at least a portion of the light is reflected by the partially reflective layer 2960 and the light is captured by the camera 2980.

For comparison, illuminating light rays 2973 from the light source 2958 are also shown being reflected by the partially reflective layer 2960. Where the angle of the illuminating light 2973 is such that the DLP mirrors, when in the “on” state, reflect the illuminating light 2973 to form image light 2969 that substantially shares the same optical axis as the light from the wearer's eye 2971. In this way, images of the wearer's eye are captured in a field of view that overlaps the field of view for the displayed image content. In contrast, light reflected by DLP mirrors in the “off” state form dark light 2975 which is directed substantially to the side of the image light 2969 and the light from eye 2971. Dark light 2975 is directed toward a light trap 2962 that absorbs the dark light to improve the contrast of the displayed image as has been described above in this specification.

In an embodiment, partially reflective layer 2960 is a reflective polarizer. The light that is reflected from the eye 2971 can then be polarized prior to entering the corrective wedge 2966 (e.g., with an absorptive polarizer between the upper module 202 and the lower module 204), with a polarization orientation relative to the reflective polarizer that enables the light reflected from the eye 2971 to substantially be transmitted by the reflective polarizer. A quarter wave retarder layer 2957 is then included adjacent to the DLP 2955 (as previously disclosed in FIG. 3b ) so that the light reflected from the eye 2971 passes through the quarter wave retarder layer 2957 once before being reflected by the plurality of DLP mirrors in the “no power” state and then passes through a second time after being reflected. By passing through the quarter wave retarder layer 2957 twice, the polarization state of the light from the eye 2971 is reversed, such that when it is incident upon the reflective polarizer, the light from the eye 2971 is then substantially reflected toward the camera 2980. By using a partially reflective layer 2960 that is a reflective polarizer and polarizing the light from the eye 2971 prior to entering the corrective wedge 2964, losses attributed to the partially reflective layer 2960 are reduced.

FIG. 28c shows the case wherein the DLP mirrors are simultaneously in the “no power” state, this mode of operation can be particularly useful when the HWC 102 is first put onto the head of the wearer. When the HWC 102 is first put onto the head of the wearer, it is not necessary to display an image yet. As a result, the DLP can be in a “no power” state for all the DLP mirrors and an image of the wearer's eyes can be captured. The captured image of the wearer's eye can then be compared to a database, using iris identification techniques, or other eye pattern identification techniques to determine, for example, the identity of the wearer.

In a further embodiment illustrated by FIG. 29 all of the DLP mirrors are put into the “no power” state for a portion of a frame time (e.g. 50% of a frame time for the displayed digital content image) and the capture of the eye image is synchronized to occur at the same time and for the same duration. By reducing the time that the DLP mirrors are in the “no power” state, the time where light is scattered by the DLP mirrors being in the “no power” state is reduced such that the wearer doesn't perceive a change in the displayed image quality. This is possible because the DLP mirrors have a response time on the order of microseconds while typical frame times for a displayed image are on the order of 0.016 seconds. This method of capturing images of the wearer's eye can be used periodically to capture repetitive images of the wearer's eye. For example, eye images could be captured for 50% of the frame time of every 10^(th) frame displayed to the wearer. In another example, eye images could be captured for 10% of the frame time of every frame displayed to the wearer.

Alternately, the “no power” state can be applied to a subset of the DLP mirrors (e.g. 10% of the DLP mirrors) within while another subset is in busy generating image light for content to be displayed. This enables the capture of an eye image(s) during the display of digital content to the wearer. The DLP mirrors used for eye imaging can, for example, be distributed randomly across the area of the DLP to minimize the impact on the quality of the digital content being displayed to the wearer. To improve the displayed image perceived by the wearer, the individual DLP mirrors put into the “no power” state for capturing each eye image, can be varied over time such as in a random pattern, for example. In yet a further embodiment, the DLP mirrors put into the “no power” state for eye imaging may be coordinated with the digital content in such a way that the “no power” mirrors are taken from a portion of the image that requires less resolution.

In the embodiments of the invention as illustrated in FIGS. 9 and 29, in both cases the reflective surfaces provided by the DLP mirrors do not preserve the wavefront of the light from the wearer's eye so that the image quality of captured image of the eye is somewhat limited. It may still be useful in certain embodiments, but it is somewhat limited. This is due to the DLP mirrors not being constrained to be on the same plane. In the embodiment illustrated in FIG. 9, the DLP mirrors are tilted so that they form rows of DLP mirrors that share common planes. In the embodiment illustrated in FIG. 29, the individual DLP mirrors are not accurately positioned to be in the same plane since they are not in contact with the substrate. Examples of advantages of the embodiments associated with FIG. 29 are: first, the camera 2980 can be located between the DLP 2955 and the illumination light source 2958 to provide a more compact upper module 202. Second, the polarization state of the light reflected from the eye 2971 can be the same as that of the image light 2969 so that the optical path of the light reflected from the eye and the image light can be the same in the lower module 204.

FIG. 30 shows an illustration of an embodiment for displaying images to the wearer and simultaneously capturing images of the wearer's eye, wherein light from the eye 2971 is reflected towards a camera 3080 by the partially reflective layer 2960. The partially reflective layer 2960 can be an optically flat layer such that the wavefront of the light from the eye 2971 is preserved and as a result, higher quality images of the wearer's eye can be captured. In addition, since the DLP 2955 is not included in the optical path for the light from the eye 2971, and the eye imaging process shown in FIG. 30 does not interfere with the displayed image, images of the wearer's eye can be captured independently (e.g. with independent of timing, impact on resolution, or pixel count used in the image light) from the displayed images.

In the embodiment illustrated in FIG. 30, the partially reflective layer 2960 is a reflective polarizer, the illuminating light 2973 is polarized, the light from the eye 2971 is polarized and the camera 3080 is located behind a polarizer 3085. The polarization axis of the illuminating light 2973 and the polarization axis of the light from the eye are oriented perpendicular to the transmission axis of the reflective polarizer so that they are both substantially reflected by the reflective polarizer. The illumination light 2973 passes through a quarter wave layer 2957 before being reflected by the DLP mirrors in the DLP 2955. The reflected light passes back through the quarter wave layer 2957 so that the polarization states of the image light 2969 and dark light 2975 are reversed in comparison to the illumination light 2973. As such, the image light 2969 and dark light 2975 are substantially transmitted by the reflective polarizer. Where the DLP mirrors in the “on” state provide the image light 2969 along an optical axis that extends into the lower optical module 204 to display an image to the wearer. At the same time, DLP mirrors in the “off” state provide the dark light 2975 along an optical axis that extends to the side of the upper optics module 202. In the region of the corrective wedge 2966 where the dark light 2975 is incident on the side of the upper optics module 202, an absorptive polarizer 3085 is positioned with its transmission axis perpendicular to the polarization axis of the dark light and parallel to the polarization axis of the light from the eye so that the dark light 2975 is absorbed and the light from the eye 2971 is transmitted to the camera 3080. FIG. 31 shows an illustration of another embodiment of a system for displaying images and simultaneously capturing image of the wearer's eye that is similar to the one shown in FIG. 30. The difference in the system shown in FIG. 31 is that the light from the eye 2971 is subjected to multiple reflections before being captured by the camera 3180. To enable the multiple reflections, a mirror 3187 is provided behind the absorptive polarizer 3185.

Therefore, the light from the eye 2971 is polarized prior to entering the corrective wedge 2966 with a polarization axis that is perpendicular to the transmission axis of the reflective polarizer that comprises the partially reflective layer 2960. In this way, the light from the eye 2971 is reflected first by the reflective polarizer, reflected second by the mirror 3187 and reflected third by the reflective polarizer before being captured by the camera 3180. While the light from the eye 2971 passes through the absorptive polarizer 3185 twice, since the polarization axis of the light from the eye 2971 is oriented parallel to the polarization axis of the light from the eye 2971, it is substantially transmitted by the absorptive polarizer 3185. As with the system described in connection with FIG. 30, the system shown in FIG. 31 includes an optically flat partially reflective layer 2960 that preserves the wavefront of the light from the eye 2971 so that higher quality images of the wearer's eye can be captured. Also, since the DLP 2955 is not included in the optical path for the light reflected from the eye 2971 and the eye imaging process shown in FIG. 31 does not interfere with the displayed image, images of the wearer's eye can be captured independently from the displayed images.

FIG. 32 shows an illustration of a system for displaying images and simultaneously capturing images of the wearer's eye that includes a beam splitter plate 3212 comprised of a reflective polarizer, which is held in air between the light source 2958, the DLP 2955 and the camera 3280. The illumination light 2973 and the light from the eye 2971 are both polarized with polarization axes that are perpendicular to the transmission axis of the reflective polarizer. As a result, both the illumination light 2973 and the light from the eye 2971 are substantially reflected by the reflective polarizer. The illumination light 2873 is reflected toward the DLP 2955 by the reflective polarizer and split into image light 2969 and dark light 3275 depending on whether the individual DLP mirrors are respectively in the “on” state or the “off” state. By passing through the quarter wave layer 2957 twice, the polarization state of the illumination light 2973 is reversed in comparison to the polarization state of the image light 2969 and the dark light 3275. As a result, the image light 2969 and the dark light 3275 are then substantially transmitted by the reflective polarizer. The absorptive polarizer 3285 at the side of the beam splitter plate 3212 has a transmission axis that is perpendicular to the polarization axis of the dark light 3275 and parallel to the polarization axis of the light from the eye 2971 so that the dark light 3275 is absorbed and the light from the eye 2971 is transmitted to the camera 3280. As in the system shown in FIG. 30, the system shown in FIG. 31 includes an optically flat beam splitter plate 3212 that preserves the wavefront of the light from the eye 2971 so that higher quality images of the wearer's eye can be captured. Also, since the DLP 2955 is not included in the optical path for the light from the eye 2971 and the eye imaging process shown in FIG. 31 does not interfere with the displayed image, images of the wearer's eye can be captured independently from the displayed images.

Eye imaging systems where the polarization state of the light from the eye 2971 needs to be opposite to that of the image light 2969 (as shown in FIGS. 30, 31 and 32), need to be used with lower modules 204 that include combiners that will reflect both polarization states. As such, these upper modules 202 are best suited for use with the lower modules 204 that include combiners that are reflective regardless of polarization state, examples of these lower modules are shown in FIGS. 6, 8 a, 8 b, 8 c and 24-27.

In a further embodiment shown in FIG. 33, the partially reflective layer 3360 is comprised of a reflective polarizer on the side facing the illumination light 2973 and a short pass dichroic mirror on the side facing the light from the eye 3371 and the camera 3080. Where the short pass dichroic mirror is a dielectric mirror coating that transmits visible light and reflects infrared light. The partially reflective layer 3360 can be comprised of a reflective polarizer bonded to the inner surface of the illumination wedge 2964 and a short pass dielectric mirror coating on the opposing inner surface of the corrective wedge 2966, wherein the illumination wedge 2964 and the corrective wedge 2966 are then optically bonded together. Alternatively, the partially reflective layer 3360 can be comprised of a thin substrate that has a reflective polarizer bonded to one side and a short pass dichroic mirror coating on the other side, where the partially reflective layer 3360 is then bonded between the illumination wedge 2964 and the corrective wedge 2966. In this embodiment, an infrared light is included to illuminate the eye so that the light from the eye and the images captured of the eye are substantially comprised of infrared light. The wavelength of the infrared light is then matched to the reflecting wavelength of the shortpass dichroic mirror and the wavelength that the camera can capture images, for example an 800 nm wavelength can be used. In this way, the short pass dichroic mirror transmits the image light and reflects the light from the eye. The camera 3080 is then positioned at the side of the corrective wedge 2966 in the area of the absorbing light trap 3382, which is provided to absorb the dark light 2975. By positioning the camera 3080 in a depression in the absorbing light trap 3382, scattering of the dark light 2975 by the camera 3080 can be reduced so that higher contrast images can be displayed to the wearer. An advantage of this embodiment is that the light from the eye need not be polarized, which can simplify the optical system and increase efficiency for the eye imaging system.

In yet another embodiment shown in FIG. 32a a beam splitter plate 3222 is comprised of a reflective polarizer on the side facing the illumination light 2973 and a short pass dichroic mirror on the side facing the light from the eye 3271 and the camera 3280. An absorbing surface 3295 is provided to trap the dark light 3275 and the camera 3280 is positioned in an opening in the absorbing surface 3295. In this way the system of FIG. 32 can be made to function with unpolarized light from the eye 3271.

In embodiments directed to capturing images of the wearer's eye, light to illuminate the wearer's eye can be provided by several different sources including: light from the displayed image (i.e. image light); light from the environment that passes through the combiner or other optics; light provided by a dedicated eye light, etc. FIGS. 34 and 34 a show illustrations of dedicated eye illumination lights 3420. FIG. 34 shows an illustration from a side view in which the dedicated illumination eye light 3420 is positioned at a corner of the combiner 3410 so that it doesn't interfere with the image light 3415. The dedicated eye illumination light 3420 is pointed so that the eye illumination light 3425 illuminates the eyebox 3427 where the eye 3430 is located when the wearer is viewing displayed images provided by the image light 3415. FIG. 34a shows an illustration from the perspective of the eye of the wearer to show how the dedicated eye illumination light 3420 is positioned at the corner of the combiner 3410. While the dedicated eye illumination light 3420 is shown at the upper left corner of the combiner 3410, other positions along one of the edges of the combiner 3410, or other optical or mechanical components, are possible as well. In other embodiments, more than one dedicated eye light 3420 with different positions can be used. In an embodiment, the dedicated eye light 3420 is an infrared light that is not visible by the wearer (e.g. 800 nm) so that the eye illumination light 3425 doesn't interfere with the displayed image perceived by the wearer.

FIG. 35 shows a series of illustrations of captured eye images that show the eye glint (i.e. light that reflects off the front of the eye) produced by a dedicated eye light. In this embodiment of the invention, captured images of the wearer's eye are analyzed to determine the relative positions of the iris 3550, pupil, or other portion of the eye, and the eye glint 3560. The eye glint is a reflected image of the dedicated eye light 3420 when the dedicated light is used. FIG. 35 illustrates the relative positions of the iris 3550 and the eye glint 3560 for a variety of eye positions. By providing a dedicated eye light 3420 in a fixed position, combined with the fact that the human eye is essentially spherical, or at least a reliably repeatable shape, the eye glint provides a fixed reference point against which the determined position of the iris can be compared to determine where the wearer is looking, either within the displayed image or within the see-through view of the surrounding environment. By positioning the dedicated eye light 3420 at a corner of the combiner 3410, the eye glint 3560 is formed away from the iris 3550 in the captured images. As a result, the positions of the iris and the eye glint can be determined more easily and more accurately during the analysis of the captured images, since they do not interfere with one another. In a further embodiment, the combiner includes an associated cut filter that prevents infrared light from the environment from entering the HWC and the camera is an infrared camera, so that the eye glint is only provided by light from the dedicated eye light. For example, the combiner can include a low pass filter that passes visible light while absorbing infrared light and the camera can include a high pass filter that absorbs visible light while passing infrared light.

In an embodiment of the eye imaging system, the lens for the camera is designed to take into account the optics associated with the upper module 202 and the lower module 204. This is accomplished by designing the camera to include the optics in the upper module 202 and optics in the lower module 204, so that a high MTF image is produced, at the image sensor in the camera, of the wearer's eye. In yet a further embodiment, the camera lens is provided with a large depth of field to eliminate the need for focusing the camera to enable sharp image of the eye to be captured. Where a large depth of field is typically provided by a high f/# lens (e.g. f/#>5). In this case, the reduced light gathering associated with high f/# lenses is compensated by the inclusion of a dedicated eye light to enable a bright image of the eye to be captured. Further, the brightness of the dedicated eye light can be modulated and synchronized with the capture of eye images so that the dedicated eye light has a reduced duty cycle and the brightness of infrared light on the wearer's eye is reduced.

In a further embodiment, FIG. 36a shows an illustration of an eye image that is used to identify the wearer of the HWC. In this case, an image of the wearer's eye 3611 is captured and analyzed for patterns of identifiable features 3612. The patterns are then compared to a database of eye images to determine the identity of the wearer. After the identity of the wearer has been verified, the operating mode of the HWC and the types of images, applications, and information to be displayed can be adjusted and controlled in correspondence to the determined identity of the wearer. Examples of adjustments to the operating mode depending on who the wearer is determined to be or not be include: making different operating modes or feature sets available, shutting down or sending a message to an external network, allowing guest features and applications to run, etc.

FIG. 36b is an illustration of another embodiment using eye imaging, in which the sharpness of the displayed image is determined based on the eye glint produced by the reflection of the displayed image from the wearer's eye surface. By capturing images of the wearer's eye 3611, an eye glint 3622, which is a small version of the displayed image can be captured and analyzed for sharpness. If the displayed image is determined to not be sharp, then an automated adjustment to the focus of the HWC optics can be performed to improve the sharpness. This ability to perform a measurement of the sharpness of a displayed image at the surface of the wearer's eye can provide a very accurate measurement of image quality. Having the ability to measure and automatically adjust the focus of displayed images can be very useful in augmented reality imaging where the focus distance of the displayed image can be varied in response to changes in the environment or changes in the method of use by the wearer.

An aspect of the present invention relates to controlling the HWC 102 through interpretations of eye imagery. In embodiments, eye-imaging technologies, such as those described herein, are used to capture an eye image or series of eye images for processing. The image(s) may be process to determine a user intended action, an HWC predetermined reaction, or other action. For example, the imagery may be interpreted as an affirmative user control action for an application on the HWC 102. Or, the imagery may cause, for example, the HWC 102 to react in a pre-determined way such that the HWC 102 is operating safely, intuitively, etc.

Another aspect of the present invention relates to measuring the brightness of content or a content portion and adjusting the brightness of the content. When using a DLP display in a head mounted display, light is provided by a light source and is reflected by the DLP mirrors either to the user's eye or to a light trap. The brightness of a pixel in an image displayed to the user's eye is determined by the relative time within a duty cycle that the light is reflected to the user's eye relative to the time that the light is reflected to the light trap. Wherein the maximum brightness of the pixel is determined by the brightness of the light source. The invention provides a method for measuring the brightness of the light source by measuring the brightness of light reflected to the light trap and determining the brightness of the image presented to the user in correspondence to this measurement.

Equation 1 illustrates the relationship associated with the brightness of a pixel as perceived by a user's eye in a head mounted display.

Bp=baRt/f  Equation 1

Wherein Bp is the perceived pixel brightness by the user, a is the area of the pixel, b is the brightness of the light source, R is the reflectivity of the DLP mirrors, tis the time that the pixel light is reflected toward the user's eye (also known as on-state light) and f is the frame time that an image is displayed (as a result f=t+d where d is the time that the pixel light is reflected toward the light trap, which is also known as off-state light). For a single pixel, t/f represents the % of time within a frame time that the light is directed toward the user's eye. Since the frame time f is typically a shorter period of time than the human eye can detect (e.g. 0.033 sec for 30 frames/sec), longer tis perceived as a brighter pixel. Within an image, a higher code value equates to a brighter pixel and hence a longer t (i.e. t/f=Cpixel/Cmax where Cpixel is the pixel code value and Cmax is the maximum code value possible for pixels in the image). In some cases, tis broken into multiple subtimes within a frame time that together add to t to further reduce any perceptible flicker in the image.

The invention provides a brightness sensor within the light trap in the optics of the head mounted display for determining the brightness of the light source b so the brightness of displayed image provided to the user's eye can be controlled. Where the brightness sensor measures the light provided by multiple pixels to the light trap as related in Equation 2

Bm=(Bmax−Bp)pm  Equation 2

Wherein Bmax is the maximum brightness that a pixel can have when it has the maximum code value allowed by the DLP and associated electronics (Cmax) in the image (Bmax=b a R because for C max, t=f) and Bm is the brightness measured by the brightness sensor in the light trap. In addition, pm is the number of pixels that reflect light from the DLP such that their reflected light is sensed by the brightness sensor. Typically pm will be some portion of the total number of pixels in the image, ptot (e.g. pm=0.25 ptot). However the brightness sensor can be large enough to cover the entire area of the light trap wherein pm=ptot.

The brightness of the light source b can then be determined as a relationship between the brightness measured by the brightness sensor, the portion of the image pixels measured, the area and reflectivity of the DLP mirrors and the average code values of the measured image pixels as for example shown in Equation 3. Where Cavg is the average code value for the measured image pixels. Thus the embodiments of the present invention provides a method for determining the brightness of the light source in correspondence to a measurement of the light reflected toward the light trap, some properties of the DLP and a determined average code value in the portion of the image that is measured. Wherein the properties of the DLP (pm, a and R) are a constant associated with the DLP and the optics of the head mounted display. Cmax is a constant associated with the DLP and the associated electronics. Cavg must be determined for each image that is displayed and from which a measure of brightness is obtained. The measurement of light source brightness b can be used to adjust the voltage or current applied to the LEDs or adjust the pulse width modulation of the LEDs or tune the pulse width modulation of the mirrors in the DLP. Measurements of the light source brightness can be done continuously for each frame when displaying a video in a head mounted display.

b=(Bm/(pmaR))(Cmax/(Cmax−Cavg))  Equation 3

The brightness of the displayed image provided to the eye of the user, Bdi, can then be determined for example based on the % of pixels in the image that are measured by the brightness sensor and the difference between the maximum brightness Bmax and the measured brightness Bm as illustrated for example in Equation 4.

Bdi=(ptot/pm)(Bmax−Bm)  Equation 4

Where brightness measurements can be in terms of a variety of units including: candelas/square meter and lumens. The brightness measurements can be used to determine the brightness of the displayed image in a way that gives a direct and accurate measurement of the display light provided by the head mounted display to the user's eye. By providing a direct measurement, adjustments to the brightness of the light source can be made for example to compensate for changes in voltage within the head mounted display such as when the environmental temperature changes or a battery in the head mounted display is losing its charge. Since the brightness measurement is based on a direct measurement of the light provided by individual pixels, the number of pixels measured by the brightness sensor can be relatively small. The brightness sensor can be located in any area that the off-state light impinges upon such as, for example, within a light trap shown in FIGS. 5b-5e , 29, 30, 31, 32, 32 a, 33, 53, and 54. The brightness sensor should be absorbing to prevent stray light from reflections of the off-state light.

In a further embodiment, when the head mounted display includes a see-through view of the environment where the displayed image is overlaid on the see-through view so the user sees a combined image, the brightness measurement system of the invention is combined with a measurement of the brightness of the see-through view Bstv. Wherein, the brightness of the see-through view Bstv is determined by the brightness of the environment (Benv) and the optical density of the optics (OD) between the user's eye and the environment as shown in Equation 5. The optics included in the see-through view may include a tinted layer, a photochromic layer or an adjustable optical density layer.

Bstv=OD Benv  Equation 5

The brightness of the displayed image Bdi can then be adjusted in relation to Bstv by adjusting the brightness of the light source b or by scaling the code values in the image. The brightness of the see-through view Bstv can be changed by changing a portion of the see-through optics to change the tinted layer, allowing the photochromic layer to automatically change optical density due to changes in the brightness of the environment, or by adjusting the optical density of the adjustable optical density layer or a combination thereof as the brightness of the environment changes.

Equation 6 is an example of the relationship wherein the brightness of the displayed image Bdi can be changed in relation to the measured brightness of the environment Benv or the measured brightness of the see-through view Bstv. Wherein k is a controlling factor that can be a constant that is associated with the operating function of the head mounted display. As such, k can change as the operating function of the head mounted display changes. For example, if the user is not moving and a wide portion of the field of view is being used to display an image such as a movie or email, k may be a larger number such as 10 and the user will be only able to see a minimal view of the environment. However, in another example, the user may be moving rapidly and a narrow portion of the field of view is being used to display an image (or the majority of the displayed image is black so that the user only sees light from the environment in the majority of the field of view), k may be a small number such as 0.5, or even 0.0 so that the user is provided with a more easily distinguishable view of the environment. In a further example, k may be a larger number when the user is determined to be holding his head to look straight ahead thereby indicating a longer range see-through view, and k may be smaller when the user is determined to be holding his head to look down thereby indicating a shorter range see through.

Bdi=kBstv  Equation 6

Thus the invention provides a method for control of the brightness of the light source in relation to the brightness of the environment or the brightness of the see-through view, and the operating function of the head mounted display. Wherein the brightness of the light source can be measured as previously described and actively controlled to maintain the relationship to the brightness of the environment or the brightness of the see-through view.

In an embodiment of the invention, k is automatically changed by the head mounted display in response to: sensed changes in the environment; changes in operating mode; sensed changes in what the user is looking at; sensed changes in where the user is located; sensed patterns in head movement; sensed changes in the gaze direction of the user; sensed changes in the vertical gaze angle of the user; or sensed changes in the speed of movement of the user. Wherein sensed changes in the way the user is acting indicate intended changes of the way the user would like to operate the head mounted display.

In another embodiment, the measurement of Bstv is provided by a brightness sensor located behind the tinted layer, photochromic layer or adjustable optical density layer. This method of measurement provides a more direct measurement of the brightness of the see-through view.

In yet another embodiment, a relative measurement of Bstv+Bdi is obtained by measuring the brightness of the light reflected by the user's eye. This method of measurement provides a more direct relative measurement of the brightness of the combined displayed image and the see-through view as seen by the user.

FIG. 37 illustrates a eye imagery process that involves imaging the HWC 102 wearer's eye(s) and processing the images (e.g. through eye imaging technologies described herein) to determine in what position 3702 the eye is relative to its neutral or forward looking position and/or the FOV 3708. The process may involve a calibration step where the user is instructed, through guidance provided in the FOV of the HWC 102, to look in certain directions such that a more accurate prediction of the eye position relative to areas of the FOV can be made. In the event the wearer's eye is determined to be looking towards the right side of the FOV 3708 (as illustrated in FIG. 37, the eye is looking out of the page) a virtual target line may be established to project what in the environment the wearer may be looking towards or at. The virtual target line may be used in connection with an image captured by camera on the HWC 102 that images the surrounding environment in front of the wearer. In embodiments, the field of view of the camera capturing the surrounding environment matches, or can be matched (e.g. digitally), to the FOV 3708 such that making the comparison is made more clear. For example, with the camera capturing the image of the surroundings in an angle that matches the FOV 3708 the virtual line can be processed (e.g. in 2d or 3d, depending on the camera images capabilities and/or the processing of the images) by projecting what surrounding environment objects align with the virtual target line. In the event there are multiple objects along the virtual target line, focal planes may be established corresponding to each of the objects such that digital content may be placed in an area in the FOV 3708 that aligns with the virtual target line and falls at a focal plane of an intersecting object. The user then may see the digital content when he focuses on the object in the environment, which is at the same focal plane. In embodiments, objects in line with the virtual target line may be established by comparison to mapped information of the surroundings.

In embodiments, the digital content that is in line with the virtual target line may not be displayed in the FOV until the eye position is in the right position. This may be a predetermined process. For example, the system may be set up such that a particular piece of digital content (e.g. an advertisement, guidance information, object information, etc.) will appear in the event that the wearer looks at a certain object(s) in the environment. A virtual target line(s) may be developed that virtually connects the wearer's eye with an object(s) in the environment (e.g. a building, portion of a building, mark on a building, gps location, etc.) and the virtual target line may be continually updated depending on the position and viewing direction of the wearer (e.g. as determined through GPS, e-compass, IMU, etc.) and the position of the object. When the virtual target line suggests that the wearer's pupil is substantially aligned with the virtual target line or about to be aligned with the virtual target line, the digital content may be displayed in the FOV 3704.

In embodiments, the time spent looking along the virtual target line and/or a particular portion of the FOV 3708 may indicate that the wearer is interested in an object in the environment and/or digital content being displayed. In the event there is no digital content being displayed at the time a predetermined period of time is spent looking at a direction, digital content may be presented in the area of the FOV 3708. The time spent looking at an object may be interpreted as a command to display information about the object, for example. In other embodiments, the content may not relate to the object and may be presented because of the indication that the person is relatively inactive. In embodiments, the digital content may be positioned in proximity to the virtual target line, but not in-line with it such that the wearer's view of the surroundings are not obstructed but information can augment the wearer's view of the surroundings. In embodiments, the time spent looking along a target line in the direction of displayed digital content may be an indication of interest in the digital content. This may be used as a conversion event in advertising. For example, an advertiser may pay more for an add placement if the wearer of the HWC 102 looks at a displayed advertisement for a certain period of time. As such, in embodiments, the time spent looking at the advertisement, as assessed by comparing eye position with the content placement, target line or other appropriate position may be used to determine a rate of conversion or other compensation amount due for the presentation.

An aspect of the invention relates to removing content from the FOV of the HWC 102 when the wearer of the HWC 102 apparently wants to view the surrounding environments clearly. FIG. 38 illustrates a situation where eye imagery suggests that the eye has or is moving quickly so the digital content 3804 in the FOV 3808 is removed from the FOV 3808. In this example, the wearer may be looking quickly to the side indicating that there is something on the side in the environment that has grabbed the wearer's attention. This eye movement 3802 may be captured through eye imaging techniques (e.g. as described herein) and if the movement matches a predetermined movement (e.g. speed, rate, pattern, etc.) the content may be removed from view. In embodiments, the eye movement is used as one input and HWC movements indicated by other sensors (e.g. IMU in the HWC) may be used as another indication. These various sensor movements may be used together to project an event that should cause a change in the content being displayed in the FOV.

Another aspect of the present invention relates to determining a focal plane based on the wearer's eye convergence. Eyes are generally converged slightly and converge more when the person focuses on something very close. This is generally referred to as convergence. In embodiments, convergence is calibrated for the wearer. That is, the wearer may be guided through certain focal plane exercises to determine how much the wearer's eyes converge at various focal planes and at various viewing angles. The convergence information may then be stored in a database for later reference. In embodiments, a general table may be used in the event there is no calibration step or the person skips the calibration step. The two eyes may then be imaged periodically to determine the convergence in an attempt to understand what focal plane the wearer is focused on. In embodiments, the eyes may be imaged to determine a virtual target line and then the eye's convergence may be determined to establish the wearer's focus, and the digital content may be displayed or altered based thereon.

FIG. 39 illustrates a situation where digital content is moved 3902 within one or both of the FOVs 3908 and 3910 to align with the convergence of the eyes as determined by the pupil movement 3904. By moving the digital content to maintain alignment, in embodiments, the overlapping nature of the content is maintained so the object appears properly to the wearer. This can be important in situations where 3D content is displayed.

An aspect of the present invention relates to controlling the HWC 102 based on events detected through eye imaging. A wearer winking, blinking, moving his eyes in a certain pattern, etc. may, for example, control an application of the HWC 102. Eye imaging (e.g. as described herein) may be used to monitor the eye(s) of the wearer and once a pre-determined pattern is detected an application control command may be initiated.

An aspect of the invention relates to monitoring the health of a person wearing a HWC 102 by monitoring the wearer's eye(s). Calibrations may be made such that the normal performance, under various conditions (e.g. lighting conditions, image light conditions, etc.) of a wearer's eyes may be documented. The wearer's eyes may then be monitored through eye imaging (e.g. as described herein) for changes in their performance. Changes in performance may be indicative of a health concern (e.g. concussion, brain injury, stroke, loss of blood, etc.). If detected the data indicative of the change or event may be communicated from the HWC 102.

Aspects of the present invention relate to security and access of computer assets (e.g. the HWC itself and related computer systems) as determined through eye image verification. As discussed herein elsewhere, eye imagery may be compared to known person eye imagery to confirm a person's identity. Eye imagery may also be used to confirm the identity of people wearing the HWCs 102 before allowing them to link together or share files, streams, information, etc.

An aspect of the present invention relates to securely linking HWC 102 and securely sharing files, streams, etc. (referred to generally as file sharing) with other HWC's 102 and/or other computers. Eye imaging, position, and tracking described herein elsewhere may be used in connection with the secure linking and file sharing. For example, a first HWC 102 may only be permitted to securely link with another HWC 102 if the wearer of the other HWC 102 is verified as a known person of a certain security level. In embodiments, the security level may be a government determined security level, a known person, a known friend, etc. Eye imaging may be used to identify the other HWCs 102 that may be allowed for sharing. For example, GPS or other location technologies may be used to identify other HWC's 102 in the proximity of a first HWC 102 and those proximal HWC's may be sorted into ones verified as secure HWC's, as verified by eye imaging, for example, and ones not verified. The sorted information or portion thereof may be presented in the first HWC 102 such that the wearer of the first HWC 102 can select secure sharing partners. Other sensor information may be used in connection with the secure sharing process. For example, identifying that two HWC's 102 are looking at one another (e.g. through e-compass readings, or HWC 102 forward facing camera image capture processing, etc.) may indicate that the two would like to share files or otherwise link communications and this information may be used in connection with the eye imaging verification for the secure sharing process. Similarly, facial recognition, biometric information (e.g. heart rate signature, lung signature, etc.), near field communication identification, gestures by and between people wearing the HWC's, external user interfaces, voice commands, voice signatures, light emission signatures/signals, wireless communication signals (e.g. encrypted signals/commands), etc. may be used in combination with eye imaging and each other as a way of identifying potential secure share partners and sharing. In the event secure share partner(s) are identified, linking may be done automatically or through a user interface action, for example. In the event a user action is required, the display in the HWC 102 may display indications of who is a potential secure share partner by presented the indications on a map, through AR, or otherwise. The AR interface may involve presenting the indication in at positions in the field of view of the HWC 102 that are indicative of a GPS location of the potential secure sharing partner (as described herein elsewhere). For further information on secure linking and file sharing see U.S. patent application Ser. No. 14/181,473, entitled Secure Sharing in Head Worn Computing, filed Feb. 14, 2014, which is hereby incorporated by reference herein in its entirety.

Another aspect of the present invention relates to presentation techniques relating to the presentation of a known location or person or object at the known location. In embodiments, a spatially three-dimensional target line may be established between a first HWC 102 and a known geo-spatial location (e.g. as described by a gps location or other triangulation technology). Digital content may then be presented in a position in the field of view of the HWC 102 that corresponds, or is in-line, with the target line. The digital content may further be presented such that it comes into the wearer's view when the wearer focuses on a particular focal plane in the distance. The focal plane could then be aligned with the geo-spatial location such that when the wearer looks at the geo-spatial location, which is in-line with the target line, the digital content will come into view for the wearer and indicate the location with a proper visual perspective. In embodiments, the perceived environmental position indicative of the geo-spatial location may be verified by comparing the distance and angle defined by the virtual target line. In embodiments, the verification may be done with a distance and angle measured by a range finder. This may be done to confirm that there are no obstacles in between the wearer of the HWC 102 and the geo-spatial location, for example. In the event that the verification indicates that there is an obstacle and that the geo-spatial location cannot be directly viewed by the user, the digital content indicative of the location may be altered to indicate that the location is obstructed. The digital content may indicate if the location is in close proximity to the obstruction, far from the obstruction, etc. In embodiments, an obstruction may be identified by reviewing a map or map content of the area between the user and the geo-spatial location identified for the presentation of the content. In embodiments, an obstruction may be identified by estimating distance(s) to known objects in the environment, as disclosed herein after. For further information on geo-spatial position visualizations see U.S. patent application Ser. No. 14/205,313 entitled Spatial Location Presentation in Head Worn Computing, filed Mar. 11, 2014, which is hereby incorporated by reference herein in its entirety.

A variety of use cases for eye imaging are possible based on technologies described herein. An aspect of the present invention relates to the timing of eye image capture. The timing of the capture of the eye image and the frequency of the capture of multiple images of the eye can vary dependent on the use case for the information gathered from the eye image. For example, capturing an eye image to identify the user of the HWC may be required only when the HWC has been turned ON or when the HWC determines that the HWC has been put onto a wearer's head to control the security of the HWC and the associated information that is displayed to the user. Wherein, the orientation, movement pattern, stress or position of the ear horns (or other portions of the HWC) of the HWC can be used to determine that a person has put the HWC onto their head with the intention to use the HWC. Those same parameters may be monitored in an effort to understand when the HWC is dismounted from the user's head. This may enable a situation where the capture of an eye image for identifying the wearer may be completed only when a change in the wearing status is identified. In a contrasting example, capturing eye images to monitor the health of the wearer may require images to be captured periodically (e.g. every few seconds, minutes, hours, days, etc.). For example, the eye images may be taken in minute intervals when the images are being used to monitor the health of the wearer when detected movements indicate that the wearer is exercising. In a further contrasting example, capturing eye images to monitor the health of the wearer for long-term effects may only require that eye images be captured monthly. Embodiments of the invention relate to selection of the timing and rate of capture of eye images to be in correspondence with the selected use scenario associated with the eye images. These selections may be done automatically, as with the exercise example above where movements indicate exercise, or these selections may be set manually. In a further embodiment, the selection of the timing and rate of eye image capture is adjusted automatically depending on the mode of operation of the HWC. The selection of the timing and rate of eye image capture can further be selected in correspondence with input characteristics associated with the wearer including age and health status, or sensed physical conditions of the wearer including heart rate, chemical makeup of the blood and eye blink rate.

An aspect of the present invention relates to presenting digital content in a field of view of a see-through head worn optical system at a position that is dependent on feedback from a sensor. In embodiments, the sensor provides information relating to a speed of forward motion of a person wearing the see-through head worn optical system. In embodiments, the content may be shifted to a portion of the FOV that provides for greater see-through visibility for the wearer. For example, if the wearer is walking, the content may be shifted towards the edge of the FOV so the person can focus on the surrounding environment while walking but still be able to view the content at the edges of the FOV. In other embodiments, the person may be moving very fast, driving a car, for example, and the content may be shifted even further towards the edge of the FOV, or even past the FOV such that the person can more intently focus on the environment In embodiments, when the content is shifted beyond the FOV, the content may be removed from display entirely and it may re-appear when an indication is presented that the wearer wants to view it or that the motion has slowed. For example, the wearer may use an external UI, gesture, eye control command, etc. to cause the content to come back into the FOV. In embodiments, the wearer may be able to affirmatively cause the content to be moved to a location in the FOV dependent on his needs and this may modify or over-ride the content position shift based on the person's movement speed. For example, if the wearer is driving a car and the car is moving quickly, the wearer may choose to have the content displayed closer to the middle of the FOV and over-ride the auto-shift content position function.

When a user is moving through an environment while wearing a head worn computer, the method in which information is displayed may differ depending on a variety of factors that describe the way in which the user is moving. Factors such as speed, gaze direction, rate of change of gaze direction, rate of change of movement direction and the type of information being displayed may all affect how the user wants the information to be displayed.

In describing the method of display when moving, the pertinent information includes the heading that the user is looking along (generally referred to herein as “sight heading” or “sight vector”), the heading that the user is moving along (generally referred to herein as “movement heading” or “movement vector”) and the heading where the displayed information is visible by the user (generally referred to herein as “display heading” or “display vector”). Where headings are described in term of degrees as measured, for example, with a compass. Sight heading can be determined, for example, with an electronic compass or magnetometer in the HWC. Movement heading can be determined by multiple GPS readings, IMU readings, etc.

A method of presenting content is to provide the displayed information directly in front of the user all the time. In this case, the sight heading is the same as the display heading. This method can be less than ideal when the user is moving because the displayed information interferes with the view of the surrounding environment. With a see-through HWC, there can be times when the user would prefer to be provided with an unencumbered view of the environment. As such, there will be times when the user would prefer to not have displayed information in the see-through field of view. In embodiments, the process adjusts the display heading in response to the sight heading, movement heading and speed of movement. In further embodiments the method of the invention adjusts the display heading based on the type of information being displayed and in response to the sight heading, movement heading and speed of movement. In yet other embodiments, the method adjusts the display heading in response to indications of how the user is moving. In further embodiments, the brightness of the displayed image is reduced in response to the sight heading, movement heading and speed of movement.

Another example of when a user may not want to have displayed information presented in the see-through field of view is when some type of stimulus occurs in the adjacent vicinity such as a loud noise to the side of the user. Typically people respond to loud noises by turning their head to look toward the loud noise. At that point in time, the user would prefer to have an unencumbered view of the environment and, in embodiments, the content is removed based on the sound received at the HWC.

In another example, the user moves through an environment at various speeds. When a person is stationary, the person can look in any direction so the sight heading can change, but the movement heading doesn't change because there is no movement. If a person is walking, the person can look back and forth while moving, as such the sight heading can vary on either side of the movement heading and the sight heading can vary slowly. As the speed increases, it becomes more difficult for the person to look to the side for long periods of time so the sight heading can change more rapidly as the person glances to the side and in general the sight heading is more likely to match the movement heading. At high speed, such as running, the person needs to look directly ahead most of the time, so the sight heading matches the movement heading most of the time. When in a vehicle traveling at even greater speed, the person can only look briefly to the side when driving and most of the time must look ahead at the road where the sight heading matches the movement heading with only brief departures. Of course when the person is riding in a vehicle but not driving the vehicle, the person can look sideways for extended periods of time, as a result the sight heading can vary substantially from the movement heading.

FIG. 40 illustrates an embodiment in which digital content presented in a see-through FOV is positioned based on the speed in which the wearer is moving. When the person is not moving, as measured by sensor(s) in the HWC 102 (e.g. IMU, GPS based tracking, etc.), digital content may be presented at the stationary person content position 4004. The content position 4004 is indicated as being in the middle of the see-through FOV 4002; however, this is meant to illustrate that the digital content is positioned within the see-through FOV at a place that is generally desirable knowing that the wearer is not moving and as such the wearer's surrounding see through view can be somewhat obstructed. So, the stationary person content position, or neutral position, may not be centered in the see-through FOV; it may be positioned somewhere in the see-through FOV deemed desirable and the sensor feedback may shift the digital content from the neutral position. The movement of the digital content for a quickly moving person is also shown in FIG. 40 wherein as the person turns their head to the side, the digital content moves out of the see-through FOV to content position 4008 and then moves back as the person turns their head back. For a slowly moving person, the head movement can be more complex and as such the movement of the digital content in an out of the see-through FOV can follow a path such as that shown by content position 4010.

In embodiments, the sensor that assesses the wearer's movements may be a GPS sensor, IMU, accelerometer, etc. The content position may be shifted from a neutral position to a position towards a side edge of the field of view as the forward motion increases. The content position may be shifted from a neutral position to a position towards a top or bottom edge of the field of view as the forward motion increases. The content position may shift based on a threshold speed of the assessed motion. The content position may shift linearly based on the speed of the forward motion. The content position may shift non-linearly based on the speed of the forward motion. The content position may shift outside of the field of view. In embodiments, the content is no longer displayed if the speed of movement exceeds a predetermined threshold and will be displayed again once the forward motion slows.

In embodiments, the content position may generally be referred to as shifting; it should be understood that the term shifting encompasses a process where the movement from one position to another within the see-through FOV or out of the FOV is visible to the wearer (e.g. the content appears to slowly or quickly move and the user perceives the movement itself) or the movement from one position to another may not be visible to the wearer (e.g. the content appears to jump in a discontinuous fashion or the content disappears and then reappears in the new position).

Another aspect of the present invention relates to removing the content from the field of view or shifting it to a position within the field of view that increases the wearer's view of the surrounding environment when a sensor causes an alert command to be issued. In embodiments, the alert may be due to a sensor or combination of sensors that sense a condition above a threshold value. For example, if an audio sensor detects a loud sound of a certain pitch, content in the field of view may be removed or shifted to provide a clear view of the surrounding environment for the wearer. In addition to the shifting of the content, in embodiments, an indication of why the content was shifted may be presented in the field of view or provided through audio feedback to the wearer. For instance, if a carbon monoxide sensor detects a high concentration in the area, content in the field of view may be shifted to the side of the field of view or removed from the field of view and an indication may be provided to the wearer that there is a high concentration of carbon monoxide in the area. This new information, when presented in the field of view, may similarly be shifted within or outside of the field of view depending on the movement speed of the wearer.

FIG. 41 illustrates how content may be shifted from a neutral position 4104 to an alert position 4108. In this embodiment, the content is shifted outside of the see-through FOV 4102. In other embodiments, the content may be shifted as described herein.

Another aspect of the present invention relates to identification of various vectors or headings related to the HWC 102, along with sensor inputs, to determine how to position content in the field of view. In embodiments, the speed of movement of the wearer is detected and used as an input for position of the content and, depending on the speed, the content may be positioned with respect to a movement vector or heading (i.e. the direction of the movement), or a sight vector or heading (i.e. the direction of the wearer's sight direction). For example, if the wearer is moving very fast the content may be positioned within the field of view with respect to the movement vector because the wearer is only going to be looking towards the sides of himself periodically and for short periods of time. As another example, if the wearer is moving slowly, the content may be positioned with respect to the sight heading because the user may more freely be shifting his view from side to side.

FIG. 42 illustrates two examples where the movement vector may effect content positioning. Movement vector A 4202 is shorter than movement vector B 4210 indicating that the forward speed and/or acceleration of movement of the person associated with movement vector A 4202 is lower than the person associated with movement vector B 4210. Each person is also indicated as having a sight vector or heading 4208 and 4212. The sight vectors A 4208 and B 4210 are the same from a relative perspective. The white area inside of the black triangle in front of each person is indicative of how much time each person likely spends looking at a direction that is not in line with the movement vector. The time spent looking off angle A 4204 is indicated as being more than that of the time spent looking off angle B 4214. This may be because the movement vector speed A is lower than movement vector speed B. The faster the person moves forward the more the person tends to look in the forward direction, typically. The FOVs A 4218 and B 4222 illustrate how content may be aligned depending on the movement vectors 4202 and 4210 and sight vectors 4208 and 4212. FOV A 4218 is illustrated as presenting content in-line with the sight vector 4220. This may be due to the lower speed of the movement vector A 4202. This may also be due to the prediction of a larger amount of time spent looking off angle A 4204. FOV B 4222 is illustrated as presenting content in line with the movement vector 4224. This may be due to the higher speed of movement vector B 4210. This may also be due to the prediction of a shorter amount of time spent looking off angle B 4214.

Another aspect of the present invention relates to damping a rate of content position change within the field of view. As illustrated in FIG. 43, the sight vector may undergo a rapid change 4304. This rapid change may be an isolated event or it may be made at or near a time when other sight vector changes are occurring. The wearer's head may be turning back and forth for some reason. In embodiments, the rapid successive changes in sight vector may cause a damped rate of content position change 4308 within the FOV 4302. For example, the content may be positioned with respect to the sight vector, as described herein, and the rapid change in sight vector may normally cause a rapid content position change; however, since the sight vector is successively changing, the rate of position change with respect to the sight vector may be damped, slowed, or stopped. The position rate change may be altered based on the rate of change of the sight vector, average of the sight vector changes, or otherwise altered.

Another aspect of the present invention relates to simultaneously presenting more than one content in the field of view of a see-through optical system of a HWC 102 and positioning one content with the sight heading and one content with the movement heading. FIG. 44 illustrates two FOV's A 4414 and B 4420, which correspond respectively to the two identified sight vectors A 4402 and B 4404. FIG. 44 also illustrates an object in the environment 4408 at a position relative to the sight vectors A 4402 and B 4404. When the person is looking along sight vector A 4402, the environment object 4408 can be seen through the field of view A 4414 at position 4412. As illustrated, sight heading aligned content is presented as TEXT in proximity with the environment object 4412. At the same time, other content 4418 is presented in the field of view A 4414 at a position aligned in correspondence with the movement vector. As the movement speed increases, the content 4418 may shift as described herein. When the sight vector of the person is sight vector B 4404 the environmental object 4408 is not seen in the field of view B 4420. As a result, the sight aligned content 4410 is not presented in field of view B 4420; however, the movement aligned content 4418 is presented and is still dependent on the speed of the motion.

FIG. 45 shows an example set of data for a person moving through an environment over a path that starts with a movement heading of 0 degrees and ends with a movement heading of 114 degrees during which time the speed of movement varies from 0 m/sec to 20 m/sec. The sight heading can be seen to vary on either side of the movement heading while moving as the person looks from side to side. Large changes in sight heading occur when the movement speed is 0 m/sec when the person is standing still, followed by step changes in movement heading.

Embodiments provide a process for determining the display heading that takes into account the way a user moves through an environment and provides a display heading that makes it easy for the user to find the displayed information while also providing unencumbered see-through views of the environment in response to different movements, speed of movement or different types of information being displayed.

FIG. 46 illustrates a see-through view as may be seen when using a HWC wherein information is overlaid onto a see-through view of the environment. The tree and the building are actually in the environment and the text is displayed in the see-through display such that it appears overlaid on the environment. In addition to text information such as, for example, instructions and weather information, some augmented reality information is shown that relates to nearby objects in the environment.

In an embodiment, the display heading is determined based on speed of movement. At low speeds, the display heading may be substantially the same as the sight heading while at high speed the display heading may be substantially the same as the movement heading. In embodiments, as long as the user remains stationary, the displayed information is presented directly in front of the user and HWC. However, as the movement speed increases (e.g. above a threshold or continually, etc.) the display heading becomes substantially the same as the movement heading regardless of the direction the user is looking, so that when the user looks in the direction of movement, the displayed information is directly in front of the user and HMD and when the user looks to the side the displayed information is not visible.

Rapid changes in sight heading can be followed by a slower change in the display heading to provide a damped response to head rotation. Alternatively, the display heading can be substantially the time averaged sight heading so that the displayed information is presented at a heading that is in the middle of a series of sight headings over a period of time. In this embodiment, if the user stops moving their head, the display heading gradually becomes the same as the sight heading and the displayed information moves into the display field of view in front of the user and HMD. In embodiments, when there is a high rate of sight heading change, the process delays the effect of the time averaged sight heading on the display heading. In this way, the effect of rapid head movements on display heading is reduced and the positioning of the displayed information within the display field of view is stabilized laterally.

In another embodiment, display heading is determined based on speed of movement where at high-speed, the display heading is substantially the same as the movement heading. At mid-speed the display heading is substantially the same as a time averaged sight heading so that rapid head rotations are damped out and the display heading is in the middle of back and forth head movements.

In yet another embodiment, the type of information being displayed is included in determining how the information should be displayed. Augmented reality information that is connected to objects in the environment is given a display heading that substantially matches the sight heading. In this way, as the user rotates their head, augmented reality information comes into view that is related to objects that are in the see-through view of the environment. At the same time, information that is not connected to objects in the environment is given a display heading that is determined based on the type of movements and speed of movements as previously described in this specification.

In yet a further embodiment, when the speed of movement is determined to be above a threshold, the information displayed is moved downward in the display field of view so that the upper portion of the display field of view has less information or no information displayed to provide the user with an unencumbered see-through view of the environment.

FIGS. 47 and 48 show illustrations of a see-through view including overlaid displayed information. FIG. 47 shows the see-through view immediately after a rapid change in sight heading from the sight heading associated with the see-through view shown in FIG. 46 wherein the change in sight heading comes from a head rotation. In this case, the display heading is delayed. FIG. 48 shows how at a later time, the display heading catches up to the sight heading. The augmented reality information remains in positions within the display field of view where the association with objects in the environment can be readily made by the user.

FIG. 49 shows an illustration of a see-through view example including overlaid displayed information that has been shifted downward in the display field of view to provide an unencumbered see-through view in the upper portion of the see-through view. At the same time, augmented reality labels have been maintained in locations within the display field of view so they can be readily associated with objects in the environment.

In embodiments, the content may be positioned with respect to other types of sensors. For example, a sensor may detect an environmental condition that may be of interest and this may affect the position of the content in the display. For example, the sensor may be a chemical sensor, fire sensor, mechanical sensor, electrical sensor, audio sensor, biologic sensor, etc. and the sensor may detect the presence of danger or other condition that causes the wearer to want to view the surroundings in a clear view so the content may then shift in or out of the field of view, as described herein. In embodiments, the sensor(s) may be mounted on/in the HWC 102, local to the HWC 102, remote from the HWC 102, or otherwise located. In embodiments, the sensor input may cause content to be presented in the field of view and then the sensor input, from the same or a different sensor or combination of sensors, may cause the content to be re-positioned.

In a further embodiment, in an operating mode such as when the user is moving in an environment, digital content is presented at the side of the user's see-through FOV so that the user can only view the digital content by turning their head. In this case, when the user is looking straight ahead, such as when the movement heading matches the sight heading, the see-through view FOV does not include digital content. The user then accesses the digital content by turning their head to the side whereupon the digital content moves laterally into the user's see-through FOV. In another embodiment, the digital content is ready for presentation and will be presented if an indication for its presentation is received. For example, the information may be ready for presentation and if the sight heading or predetermined position of the HWC 102 is achieved the content may then be presented. The wearer may look to the side and the content may be presented. In another embodiment, the user may cause the content to move into an area in the field of view by looking in a direction for a predetermined period of time, blinking, winking, or displaying some other pattern that can be captured through eye imaging technologies (e.g. as described herein elsewhere).

In yet another embodiment, an operating mode is provided wherein the user can define sight headings wherein the associated see-through FOV includes digital content or does not include digital content. In an example, this operating mode can be used in an office environment where when the user is looking at a wall digital content is provided within the FOV, whereas when the user is looking toward a hallway, the FOV is unencumbered by digital content. In another example, when the user is looking horizontally digital content is provided within the FOV, but when the user looks down (e.g. to look at a desktop or a cellphone) the digital content is removed from the FOV.

Another aspect of the present invention relates to collecting and using eye position and sight heading information. Head worn computing with motion heading, sight heading, and/or eye position prediction (sometimes referred to as “eye heading” herein) may be used to identify what a wearer of the HWC 102 is apparently interested in and the information may be captured and used. In embodiments, the information may be characterized as viewing information because the information apparently relates to what the wearer is looking at. The viewing information may be used to develop a personal profile for the wearer, which may indicate what the wearer tends to look at. The viewing information from several or many HWC's 102 may be captured such that group or crowd viewing trends may be established. For example, if the movement heading and sight heading are known, a prediction of what the wearer is looking at may be made and used to generate a personal profile or portion of a crowd profile. In another embodiment, if the eye heading and location, sight heading and/or movement heading are known, a prediction of what is being looked at may be predicted. The prediction may involve understanding what is in proximity of the wearer and this may be understood by establishing the position of the wearer (e.g. through GPS or other location technology) and establishing what mapped objects are known in the area. The prediction may involve interpreting images captured by the camera or other sensors associated with the HWC 102. For example, if the camera captures an image of a sign and the camera is in-line with the sight heading, the prediction may involve assessing the likelihood that the wearer is viewing the sign. The prediction may involve capturing an image or other sensory information and then performing object recognition analysis to determine what is being viewed. For example, the wearer may be walking down a street and the camera that is in the HWC 102 may capture an image and a processor, either on-board or remote from the HWC 102, may recognize a face, object, marker, image, etc. and it may be determined that the wearer may have been looking at it or towards it.

FIG. 50 illustrates a cross section of an eyeball of a wearer of an HWC with focus points that can be associated with the eye imaging system of the invention. The eyeball 5010 includes an iris 5012 and a retina 5014. Because the eye imaging system of the invention provides coaxial eye imaging with a display system, images of the eye can be captured from a perspective directly in front of the eye and inline with where the wearer is looking. In embodiments of the invention, the eye imaging system can be focused at the iris 5012 and/or the retina 5014 of the wearer, to capture images of the external surface of the iris 5012 or the internal portions of the eye, which includes the retina 5014. FIG. 50 shows light rays 5020 and 5025 that are respectively associated with capturing images of the iris 5012 or the retina 5014 wherein the optics associated with the eye imaging system are respectively focused at the iris 5012 or the retina 5014. Illuminating light can also be provided in the eye imaging system to illuminate the iris 5012 or the retina 5014. FIG. 51 shows an illustration of an eye including an iris 5130 and a sclera 5125. In embodiments, the eye imaging system can be used to capture images that include the iris 5130 and portions the sclera 5125. The images can then be analyzed to determine color, shapes and patterns that are associated with the user. In further embodiments, the focus of the eye imaging system is adjusted to enable images to be captured of the iris 5012 or the retina 5014. Illuminating light can also be adjusted to illuminate the iris 5012 or to pass through the pupil of the eye to illuminate the retina 5014. The illuminating light can be visible light to enable capture of colors of the iris 5012 or the retina 5014, or the illuminating light can be ultraviolet (e.g. 340 nm), near infrared (e.g. 850 nm) or mid-wave infrared (e.g. 5000 nm) light to enable capture of hyperspectral characteristics of the eye.

FIG. 53 illustrates a display system that includes an eye imaging system. The display system includes a polarized light source 2958, a DLP 2955, a quarter wave film 2957 and a beam splitter plate 5345. The eye imaging system includes a camera 3280, illuminating lights 5355 and beam splitter plate 5345. Where the beam splitter plate 5345 can be a reflective polarizer on the side facing the polarized light source 2958 and a hot mirror on the side facing the camera 3280. Wherein the hot mirror reflects infrared light (e.g. wavelengths 700 to 2000 nm) and transmits visible light (e.g. wavelengths 400 to 670 nm). The beam splitter plate 5345 can be comprised of multiple laminated films, a substrate film with coatings or a rigid transparent substrate with films on either side. By providing a reflective polarizer on the one side, the light from the polarized light source 2958 is reflected toward the DLP 2955 where it passes through the quarter wave film 2957 once, is reflected by the DLP mirrors in correspondence with the image content being displayed by the DLP 2955 and then passes back through the quarter wave film 2957. In so doing, the polarization state of the light from the polarized light source is changed, so that it is transmitted by the reflective polarizer on the beam splitter plate 5345 and the image light 2971 passes into the lower optics module 204 where the image is displayed to the user. At the same time, infrared light 5357 from the illuminating lights 5355 is reflected by the hot mirror so that it passes into the lower optics module 204 where it illuminates the user's eye. Portions of the infrared light 2969 are reflected by the user's eye and this light passes back through the lower optics module 204, is reflected by the hot mirror on the beam splitter plate 5345 and is captured by the camera 3280. In this embodiment, the image light 2971 is polarized while the infrared light 5357 and 2969 can be unpolarized. In an embodiment, the illuminating lights 5355 provide two different infrared wavelengths and eye images are captured in pairs, wherein the pairs of eye images are analyzed together to improve the accuracy of identification of the user based on iris analysis.

FIG. 54 shows an illustration of a further embodiment of a display system with an eye imaging system. In addition to the features of FIG. 53, this system includes a second camera 5460. Wherein the second camera 5460 is provided to capture eye images in the visible wavelengths. Illumination of the eye can be provided by the displayed image or by see-through light from the environment. Portions of the displayed image can be modified to provide improved illumination of the user's eye when images of the eye are to be captured such as by increasing the brightness of the displayed image or increasing the white areas within the displayed image. Further, modified displayed images can be presented briefly for the purpose of capturing eye images and the display of the modified images can be synchronized with the capture of the eye images. As shown in FIG. 54, visible light 5467 is polarized when it is captured by the second camera 5460 since it passes through the beam splitter 5445 and the beam splitter 5445 is a reflective polarizer on the side facing the second camera 5460. In this eye imaging system, visible eye images can be captured by the second camera 5460 at the same time that infrared eye images are captured by the camera 3280. Wherein, the characteristics of the camera 3280 and the second camera 5460 and the associated respective images captured can be different in terms of resolution and capture rate.

FIGS. 52a and 52b illustrate captured images of eyes where the eyes are illuminated with structured light patterns. In FIG. 52a , an eye 5220 is shown with a projected structured light pattern 5230, where the light pattern is a grid of lines. A light pattern of such as 5230 can be provided by the light source 5355 show in FIG. 53 by including a diffractive or a refractive device to modify the light 5357 as are known by those skilled in the art. A visible light source can also be included for the second camera 5460 shown in FIG. 54 which can include a diffractive or refractive to modify the light 5467 to provide a light pattern. FIG. 52b illustrates how the structured light pattern of 5230 becomes distorted to 5235 when the user's eye 5225 looks to the side. This distortion comes from the fact that the human eye is not spherical in shape, instead the iris sticks out slightly from the eyeball to form a bump in the area of the iris. As a result, the shape of the eye and the associated shape of the reflected structured light pattern is different depending on which direction the eye is pointed, when images of the eye are captured from a fixed position. Changes in the structured light pattern can subsequently be analyzed in captured eye images to determine the direction that the eye is looking.

The eye imaging system can also be used for the assessment of aspects of health of the user. In this case, information gained from analyzing captured images of the iris 5012 is different from information gained from analyzing captured images of the retina 5014. Where images of the retina 5014 are captured using light 5357 that illuminates the inner portions of the eye including the retina 5014. The light 5357 can be visible light, but in an embodiment, the light 5357 is infrared light (e.g. wavelength 1 to 5 microns) and the camera 3280 is an infrared light sensor (e.g. an InGaAs sensor) or a low resolution infrared image sensor that is used to determine the relative amount of light 5357 that is absorbed, reflected or scattered by the inner portions of the eye. Wherein the majority of the light that is absorbed, reflected or scattered can be attributed to materials in the inner portion of the eye including the retina where there are densely packed blood vessels with thin walls so that the absorption, reflection and scattering are caused by the material makeup of the blood. These measurements can be conducted automatically when the user is wearing the HWC, either at regular intervals, after identified events or when prompted by an external communication. In a preferred embodiment, the illuminating light is near infrared or mid infrared (e.g. 0.7 to 5 microns wavelength) to reduce the chance for thermal damage to the wearer's eye. In another embodiment, the polarizer 3285 is antireflection coated to reduce any reflections from this surface from the light 5357, the light 2969 or the light 3275 and thereby increase the sensitivity of the camera 3280. In a further embodiment, the light source 5355 and the camera 3280 together comprise a spectrometer wherein the relative intensity of the light reflected by the eye is analyzed over a series of narrow wavelengths within the range of wavelengths provided by the light source 5355 to determine a characteristic spectrum of the light that is absorbed, reflected or scattered by the eye. For example, the light source 5355 can provide a broad range of infrared light to illuminate the eye and the camera 3280 can include: a grating to laterally disperse the reflected light from the eye into a series of narrow wavelength bands that are captured by a linear photodetector so that the relative intensity by wavelength can be measured and a characteristic absorbance spectrum for the eye can be determined over the broad range of infrared. In a further example, the light source 5355 can provide a series of narrow wavelengths of light (ultraviolet, visible or infrared) to sequentially illuminate the eye and camera 3280 includes a photodetector that is selected to measure the relative intensity of the series of narrow wavelengths in a series of sequential measurements that together can be used to determine a characteristic spectrum of the eye. The determined characteristic spectrum is then compared to known characteristic spectra for different materials to determine the material makeup of the eye. In yet another embodiment, the illuminating light 5357 is focused on the retina 5014 and a characteristic spectrum of the retina 5014 is determined and the spectrum is compared to known spectra for materials that may be present in the user's blood. For example, in the visible wavelengths 540 nm is useful for detecting hemoglobin and 660 nm is useful for differentiating oxygenated hemoglobin. In a further example, in the infrared, a wide variety of materials can be identified as is known by those skilled in the art, including: glucose, urea, alcohol and controlled substances. FIG. 55 shows a series of example spectrum for a variety of controlled substances as measured using a form of infrared spectroscopy (ThermoScientific Application Note 51242, by C. Petty, B. Garland and the Mesa Police Department Forensic Laboratory, which is hereby incorporated by reference herein). FIG. 56 shows an infrared absorbance spectrum for glucose (Hewlett Packard Company 1999, G. Hopkins, G. Mauze; “In-vivo NIR Diffuse-reflectance Tissue Spectroscopy of Human Subjects,” which is hereby incorporated by reference herein). U.S. Pat. No. 6,675,030, which is hereby incorporated by reference herein, provides a near infrared blood glucose monitoring system that includes infrared scans of a body part such as a foot. United States Patent publication 2006/0183986, which is hereby incorporated by reference herein, provides a blood glucose monitoring system including a light measurement of the retina. Embodiments of the present invention provide methods for automatic measurements of specific materials in the user's blood by illuminating at one or more narrow wavelengths into the iris of the wearer's eye and measuring the relative intensity of the light reflected by the eye to identify the relative absorbance spectrum and comparing the measured absorbance spectrum with known absorbance spectra for the specific material, such as illuminating at 540 and 660 nm to determine the level of hemoglobin present in the user's blood.

Another aspect of the present invention relates to collecting and using eye position and sight heading information. Head worn computing with motion heading, sight heading, and/or eye position prediction (sometimes referred to as “eye heading” herein) may be used to identify what a wearer of the HWC 102 is apparently interested in and the information may be captured and used. In embodiments, the information may be characterized as viewing information because the information apparently relates to what the wearer is looking at. The viewing information may be used to develop a personal profile for the wearer, which may indicate what the wearer tends to look at. The viewing information from several or many HWC's 102 may be captured such that group or crowd viewing trends may be established. For example, if the movement heading and sight heading are known, a prediction of what the wearer is looking at may be made and used to generate a personal profile or portion of a crowd profile. In another embodiment, if the eye heading and location, sight heading and/or movement heading are known, a prediction of what is being looked at may be predicted. The prediction may involve understanding what is in proximity of the wearer and this may be understood by establishing the position of the wearer (e.g. through GPS or other location technology) and establishing what mapped objects are known in the area. The prediction may involve interpreting images captured by the camera or other sensors associated with the HWC 102. For example, if the camera captures an image of a sign and the camera is in-line with the sight heading, the prediction may involve assessing the likelihood that the wearer is viewing the sign. The prediction may involve capturing an image or other sensory information and then performing object recognition analysis to determine what is being viewed. For example, the wearer may be walking down a street and the camera that is in the HWC 102 may capture an image and a processor, either on-board or remote from the HWC 102, may recognize a face, object, marker, image, etc. and it may be determined that the wearer may have been looking at it or towards it.

FIG. 57 illustrates a scene where a person is walking with a HWC 102 mounted on his head. In this scene, the person's geo-spatial location 5704 is known through a GPS sensor, which could be another location system, and his movement heading, sight heading 5714 and eye heading 5702 are known and can be recorded (e.g. through systems described herein). There are objects and a person in the scene. Person 5712 may be recognized by the wearer's HWC 102 system, the person may be mapped (e.g. the person's GPS location may be known or recognized), or otherwise known. The person may be wearing a garment or device that is recognizable. For example, the garment may be of a certain style and the HWC may recognize the style and record it's viewing. The scene also includes a mapped object 5718 and a recognized object 5720. As the wearer moves through the scene, the sight and/or eye headings may be recorded and communicated from the HWC 102. In embodiments, the time that the sight and/or eye heading maintains a particular position may be recorded. For example, if a person appears to look at an object or person for a predetermined period of time (e.g. 2 seconds or longer), the information may be communicated as gaze persistence information as an indication that the person may have been interested in the object.

In embodiments, sight headings may be used in conjunction with eye headings or eye and/or sight headings may be used alone. Sight headings can do a good job of predicting what direction a wearer is looking because many times the eyes are looking forward, in the same general direction as the sight heading. In other situations, eye headings may be a more desirable metric because the eye and sight headings are not always aligned. In embodiments herein examples may be provided with the term “eye/sight” heading, which indicates that either or both eye heading and sight heading may be used in the example.

FIG. 58 illustrates a system for receiving, developing and using movement heading, sight heading, eye heading and/or persistence information from HWC(s) 102. The server 5804 may receive heading or gaze persistence information, which is noted as persistence information 5802, for processing and/or use. The heading and/or gaze persistence information may be used to generate a personal profile 5808 and/or a group profile 5810. The personal profile 5718 may reflect the wearer's general viewing tendencies and interests. The group profile 5810 may be an assemblage of different wearer's heading and persistence information to create impressions of general group viewing tendencies and interests. The group profile 5810 may be broken into different groups based on other information such as gender, likes, dislikes, biographical information, etc. such that certain groups can be distinguished from other groups. This may be useful in advertising because an advertiser may be interested in what a male adult sports go'er is generally looking at as oppose to a younger female. The profiles 5808 and 5810 and raw heading and persistence information may be used by retailers 5814, advertisers 5818, trainers, etc. For example, an advertiser may have an advertisement posted in an environment and may be interested in knowing how many people look at the advertisement, how long they look at it and where they go after looking at it. This information may be used as conversion information to assess the value of the advertisement and thus the payment to be received for the advertisement.

In embodiments, the process involves collecting eye and/or sight heading information from a plurality of head-worn computers that come into proximity with an object in an environment. For example, a number of people may be walking through an area and each of the people may be wearing a head worn computer with the ability to track the position of the wearer's eye(s) as well as possibly the wearer's sight and movement headings. The various HWC wearing individuals may then walk, ride, or otherwise come into proximity with some object in the environment (e.g. a store, sign, person, vehicle, box, bag, etc.). When each person passes by or otherwise comes near the object, the eye imaging system may determine if the person is looking towards the object. All of the eye/sight heading information may be collected and used to form impressions of how the crowd reacted to the object. A store may be running a sale and so the store may put out a sign indicating such. The storeowners and managers may be very interested to know if anyone is looking at their sign. The sign may be set as the object of interest in the area and as people navigate near the sign, possibly determined by their GPS locations, the eye/sight heading determination system may record information relative to the environment and the sign. Once, or as, the eye/sight heading information is collected and associations between the eye headings and the sign are determined, feedback may be sent back to the storeowner, managers, advertiser, etc. as an indication of how well their sign is attracting people. In embodiments, the sign's effectiveness at attracting people's attention, as indicated through the eye/sight headings, may be considered a conversion metric and impact the economic value of the sign and/or the signs placement.

In embodiments, a map of the environment with the object may be generated by mapping the locations and movement paths of the people in the crowd as they navigate by the object (e.g. the sign). Layered on this map may be an indication of the various eye/sight headings. This may be useful in indicating wear people were in relation to the object when then viewed they object. The map may also have an indication of how long people looked at the object from the various positions in the environment and where they went after seeing the object.

In embodiments, the process involves collecting a plurality of eye/sight headings from a head-worn computer, wherein each of the plurality of eye/sight headings is associated with a different pre-determined object in an environment. This technology may be used to determine which of the different objects attracts more of the person's attention. For example, if there are three objects placed in an environment and a person enters the environment navigating his way through it, he may look at one or more of the objects and his eye/sight heading may persist on one or more objects longer than others. This may be used in making or refining the person's personal attention profile and/or it may be used in connection with other such people's data on the same or similar objects to determine an impression of how the population or crowd reacts to the objects. Testing advertisements in this way may provide good feedback of its effectiveness.

In embodiments, the process may involve capturing eye/sight headings once there is substantial alignment between the eye/sight heading and an object of interest. For example, the person with the HWC may be navigating through an environment and once the HWC detects substantial alignment or the projected occurrence of an upcoming substantial alignment between the eye/sight heading and the object of interest, the occurrence and/or persistence may be recorded for use.

In embodiments, the process may involve collecting eye/sight heading information from a head-worn computer and collecting a captured image from the head-worn computer that was taken at substantially the same time as the eye/sight heading information was captured. These two pieces of information may be used in conjunction to gain an understanding of what the wearer was looking at and possibly interested in. The process may further involve associating the eye/sight heading information with an object, person, or other thing found in the captured image. This may involve processing the captured image looking for objects or patterns. In embodiments, gaze time or persistence may be measured and used in conjunction with the image processing. The process may still involve object and/or pattern recognition, but it may also involve attempting to identify what the person gazed at for the period of time by more particularly identifying a portion of the image in conjunction with image processing.

In embodiments, the process may involve setting a pre-determined eye/sight heading from a pre-determined geospatial location and using them as triggers. In the event that a head worn computer enters the geospatial location and an eye/sight heading associated with the head worn computer aligns with the pre-determined eye/sight heading, the system may collect the fact that there was an apparent alignment and/or the system may record information identifying how long the eye/sight heading remains substantially aligned with the pre-determined eye/sight heading to form a persistence statistic. This may eliminate or reduce the need for image processing as the triggers can be used without having to image the area. In other embodiments, image capture and processing is performed in conjunction with the triggers. In embodiments, the triggers may be a series a geospatial locations with corresponding eye/sight headings such that many spots can be used as triggers that indicate when a person entered an area in proximity to an object of interest and/or when that person actually appeared to look at the object.

In embodiments, eye imaging may be used to capture images of both eyes of the wearer in order to determine the amount of convergence of the eyes (e.g. through technologies described herein elsewhere) to get an understanding of what focal plane is being concentrated on by the wearer. For example, if the convergence measurement suggests that the focal plane is within 15 feet of the wearer, than, even though the eye/sight headings may align with an object that is more than 15 feet away it may be determined that the wearer was not looking at the object. If the object were within the 15 foot suggested focal plane, the determination may be that the wearer was looking at the object.

FIG. 59 illustrates an environmentally position locked digital content 5912 that is indicative of a person's location 5902. In this disclosure the term “BlueForce” is generally used to indicate team members or members for which geo-spatial locations are known and can be used. In embodiments, “BlueForce” is a term to indicate members of a tactical arms team (e.g. a police force, secret service force, security force, military force, national security force, intelligence force, etc.). In many embodiments herein one member may be referred to as the primary or first BlueForce member and it is this member, in many described embodiments, that is wearing the HWC. It should be understood that this terminology is to help the reader and make for clear presentations of the various situations and that other members of the Blueforce, or other people, may have HWC's 102 and have similar capabilities. In this embodiment, a first person is wearing a head-worn computer 102 that has a see through field of view (“FOV”) 5914. The first person can see through the FOV to view the surrounding environment through the FOV and digital content can also be presented in the FOV such that the first person can view the actual surroundings, through the FOV, in a digitally augmented view. The other BlueForce person's location is known and is indicated at a position inside of a building at point 5902. This location is known in three dimensions, longitude, latitude and altitude, which may have been determined by GPS along with an altimeter associated with the other Blueforce person. Similarly, the location of the first person wearing the HWC 102 is also known, as indicated in FIG. 59 as point 5908. In this embodiment, the compass heading 5910 of the first person is also known. With the compass heading 5910 known, the angle in which the first person is viewing the surroundings can be estimated. A virtual target line between the location of the first person 5908 and the other person's location 5902 can be established in three dimensional space and emanating from the HWC 102 proximate the FOV 5914. The three dimensionally oriented virtual target line can then be used to present environmentally position locked digital content in the FOV 5914, which is indicative of the other person's location 5902. The environmentally position locked digital content 5902 can be positioned within the FOV 5914 such that the first person, who is wearing the HWC 102, perceives the content 5902 as locked in position within the environment and marking the location of the other person 5902.

The three dimensionally positioned virtual target line can be recalculated periodically (e.g. every millisecond, second, minute, etc.) to reposition the environmentally position locked content 5912 to remain in-line with the virtual target line. This can create the illusion that the content 5912 is staying positioned within the environment at a point that is associated with the other person's location 5902 independent of the location of the first person 5908 wearing the HWC 102 and independent of the compass heading of the HWC 102.

In embodiments, the environmentally locked digital content 5912 may be positioned with an object 5904 that is between the first person's location 5908 and the other person's location 5902. The virtual target line may intersect the object 5904 before intersecting with the other person's location 5902. In embodiments, the environmentally locked digital content 5912 may be associated with the object intersection point 5904. In embodiments, the intersecting object 5904 may be identified by comparing the two person's locations 5902 and 5908 with obstructions identified on a map. In embodiments the intersecting object 5904 may be identified by processing images captured from a camera, or other sensor, associated with the HWC 102. In embodiments, the digital content 5912 has an appearance that is indicative of being at the location of the other person 5902, at the location of the intersecting object 5904 to provide a more clear indication of the position of the other person's position 5902 in the FOV 5914.

FIG. 60 illustrates how and where digital content may be positioned within the FOV 6008 based on a virtual target line between the location of the first person 5908, who's wearing the HWC 102, and the other person 5902. In addition to positioning the content in a position within the FOV 6008 that is in-line with the virtual target line, the digital content may be presented such that it comes into focus by the first person when the first person focuses at a certain plane or distance in the environment. Presented object A 6018 is digitally generated content that is presented as an image at content position A 6012. The position 6012 is based on the virtual target line. The presented object A 6018 is presented not only along the virtual target line but also at a focal plane B 6014 such that the content at position A 6012 in the FOV 6008 comes into focus by the first person when the first person's eye 6002 focuses at something in the surrounding environment at the focal plane B 6014 distance. Setting the focal plane of the presented content provides content that does not come into focus until the eye 6002 focuses at the set focal plane. In embodiments, this allows the content at position A to be presented without when the HWC's compass is indicative of the first person looking in the direction of the other person 5902 but it will only come into focus when the first person focuses on in the direction of the other person 5902 and at the focal plane of the other person 5902.

Presented object B 6020 is aligned with a different virtual target line then presented object A 6018. Presented object B 6020 is also presented at content position B 6004 at a different focal plane than the content position A 6012. Presented content B 6020 is presented at a further focal plane, which is indicative that the other person 5902 is physically located at a further distance. If the focal planes are sufficiently different, the content at position A will come into focus at a different time than the content at position B because the two focal planes require different focus from the eye 6002.

FIG. 61 illustrates several BlueForce members at locations with various points of view from the first person's perspective. In embodiments, the relative positions, distances and obstacles may cause the digital content indicative of the other person's location to be altered. For example, if the other person can be seen by the first person through the first person's FOV, the digital content may be locked at the location of the other person and the digital content may be of a type that indicates the other person's position is being actively marked and tracked. If the other person is in relatively close proximity, but cannot be seen by the first person, the digital content may be locked to an intersecting object or area and the digital content may indicate that the actual location of the other person cannot be seen but the mark is generally tracking the other person's general position. If the other person is not within a pre-determined proximity or is otherwise more significantly obscured from the first person's view, the digital content may generally indicate a direction or area where the other person is located and the digital content may indicate that the other person's location is not closely identified or tracked by the digital content, but that the other person is in the general area.

Continuing to refer to FIG. 61, several BlueForce members are presented at various positions within an area where the first person is located. The primary BlueForce member 6102 (also referred to generally as the first person, or the person wherein the HWC with the FOV for example purposes) can directly see the BlueForce member in the open field 6104. In embodiments, the digital content provided in the FOV of the primary BlueForce member may be based on a virtual target line and virtually locked in an environment position that is indicative of the open field position of the BlueForce member 6104. The digital content may also indicate that the location of the open field Blue Force member is marked and is being tracked. The digital content may change forms if the BlueForce member becomes obscured from the vision of the primary BlueForce member or otherwise becomes unavailable for direct viewing.

BlueForce member 6108 is obscured from the primary BlueForce member's 6102 view by an obstacle that is in close proximity to the obscured member 6108. As depicted, the obscured member 6108 is in a building but close to one of the front walls. In this situation, the digital content provided in the FOV of the primary member 6102 may be indicative of the general position of the obscured member 6108 and the digital content may indicate that, while the other person's location is fairly well-marked, it is obscured so it is not as precise as if the person was in direct view. In addition, the digital content may be virtually positionally locked to some feature on the outside of the building that the obscured member is in. This may make the environmental locking more stable and also provide an indication that the location of the person is somewhat unknown.

BlueForce member 6110 is obscured by multiple obstacles. The member 6110 is in a building and there is another building 6112 in between the primary member 6102 and the obscured member 6110. In this situation, the digital content in the FOV of the primary member will be spatially quite short of the actual obscured member and as such the digital content may need to be presented in a way that indicates that the obscured member 6110 is in a general direction but that the digital marker is not a reliable source of information for the particular location of obscured member 6110.

FIG. 62 illustrates yet another method for positioning digital content within the FOV of a HWC where the digital content is intended to indicate a position of another person. This embodiment is similar to the embodiment described in connection with FIG. 62 herein. The main additional element in this embodiment is the additional step of verifying the distance between the first person 5908, the one wearing the HWC with the FOV digital content presentation of location, and the other person at location 5902. Here, the range finder may be included in the HWC and measure a distance at an angle that is represented by the virtual target line. In the event that the range finder finds an object obstructing the path of the virtual target line, the digital content presentation in the FOV may indicate such (e.g. as described herein elsewhere). In the event that the range finder confirms that there is a person or object at the end of the prescribed distance and angle defined by the virtual target line, the digital content may represent that the proper location has been marked, as described herein elsewhere.

Another aspect of the present invention relates to predicting the movement of BlueForce members to maintain proper virtual marking of the BlueForce member locations. FIG. 63 illustrates a situation where the primary BlueForce member 6302 is tracking the locations of the other BlueForce members through an augmented environment using a HWC 102, as described herein elsewhere (e.g. as described in connection with the above figures). The primary BlueForce member 6302 may have knowledge of the tactical movement plan 6308. The tactical movement plan may be maintained locally (e.g. on the HWCs 102 with sharing of the plan between the BlueForce members) or remotely (e.g. on a server and communicated to the HWC's 102, or communicated to a subset of HWC's 102 for HWC 102 sharing). In this case, the tactical plan involves the BlueForce group generally moving in the direction of the arrow 6308. The tactical plan may influence the presentations of digital content in the FOV of the HWC 102 of the primary BlueForce member. For example, the tactical plan may assist in the prediction of the location of the other Blue Force member and the virtual target line may be adjusted accordingly. In embodiments, the area in the tactical movement plan may be shaded or colored or otherwise marked with digital content in the FOV such that the primary BlueForce member can manage his activities with respect to the tactical plan. For example, he may be made aware that one or more BlueForce members are moving towards the tactical path 6308. He may also be made aware of movements in the tactical path that do not appear associated with BlueForce members.

FIG. 63 also illustrates that internal IMU sensors in the HWCs worn by the BlueForce members may provide guidance on the movement of the members 6304. This may be helpful in identifying when a GPS location should be updated and hence updating the position of the virtual marker in the FOV. This may also be helpful in assessing the validity of the GPS location. For example, if the GPS location has not updated but there is significant IMU sensor activity, the system may call into question the accuracy of the identified location. The IMU information may also be useful to help track the position of a member in the event the GPS information is unavailable. For example, dead reckoning may be used if the GPS signal is lost and the virtual marker in the FOV may indicate both indicated movements of the team member and indicate that the location identification is not ideal. The current tactical plan 6308 may be updated periodically and the updated plans may further refine what is presented in the FOV of the HWC 102.

FIG. 64 illustrates a BlueForce tracking system in accordance with the principles of the present invention. In embodiments, the BlueForce HWC's 102 may have directional antenna's that emit relatively low power directional RF signals such that other BlueForce members within the range of the relatively low power signal can receive and assess its direction and/or distance based on the strength and varying strength of the signals. In embodiments, the tracking of such RF signals can be used to alter the presentation of the virtual markers of persons locations within the FOV of HWC 102.

Another aspect of the present invention relates to monitoring the health of BlueForce members. Each BlueForce member may be automatically monitored for health and stress events. For example, the members may have a watchband as described herein elsewhere or other wearable biometric monitoring device and the device may continually monitor the biometric information and predict health concerns or stress events. As another example, the eye imaging systems described herein elsewhere may be used to monitor pupil dilatations as compared to normal conditions to predict head trauma. Each eye may be imaged to check for differences in pupil dilation for indications of head trauma. As another example, an IMU in the HWC 102 may monitor a person's walking gate looking for changes in pattern, which may be an indication of head or other trauma. Biometric feedback from a member indicative of a health or stress concern may be uploaded to a server for sharing with other members or the information may be shared with local members, for example. Once shared, the digital content in the FOF that indicates the location of the person having the health or stress event may include an indication of the health event.

FIG. 65 illustrates a situation where the primary BlueForce member 6502 is monitoring the location of the BlueForce member 6504 that has had a heath event and caused a health alert to be transmitted from the HWC 102. As described herein elsewhere, the FOV of the HWC 102 of the primary BlueForce member may include an indication of the location of the BlueForce member with the health concern 6504. The digital content in the FOV may also include an indication of the health condition in association with the location indication. In embodiments, non-biometric sensors (e.g. IMU, camera, ranger finder, accelerometer, altimeter, etc.) may be used to provide health and/or situational conditions to the BlueForce team or other local or remote persons interested in the information. For example, if one of the BlueForce members is detected as quickly hitting the ground from a standing position an alter may be sent as an indication of a fall, the person is in trouble and had to drop down, was shot, etc.

Another aspect of the present invention relates to virtually marking various prior acts and events. For example, as depicted in FIG. 66, the techniques described herein elsewhere may be used to construct a virtual prior movement path 6604 of a BlueForce member. The virtual path may be displayed as digital content in the FOV of the primary BlueForce member 6602 using methods described herein elsewhere. As the BlueForce member moved along the path 6604 he may have virtually placed an event marker 6608 such that when another member views the location the mark can be displayed as digital content. For example, the BlueForce member may inspect and clear an area and then use an external user interface or gesture to indicate that the area has been cleared and then the location would be virtually marked and shared with BlueForce members. Then, when someone wants to understand if the location was inspected he can view the location's information. As indicated herein elsewhere, if the location is visible to the member, the digital content may be displayed in a way that indicates the specific location and if the location is not visible from the person's perspective, the digital content may be somewhat different in that it may not specifically mark the location.

Another aspect of the present invention relates to the physical location at which digital content is going to be presented to a person wearing a HWC 102. In embodiments, content is presented in a FOV of a HWC 102 when the HWC 102 is at a physical location that was selected based on personal information particular to the wearer of the HWC 102. In embodiments, the physical location is identified by a geo-spatial location and an attribute in the surroundings proximate the geo-spatial location. The attribute may be something that more precisely places the content within the environment located at the geo-spatial location. The attribute may be selected such that content appears in a hallway, office, near a billboard, rooftop, outside wall, object, etc. Personal information relating to the person may be stored such that it can be retrieved during a process of determining at what physical location in the world certain digital content should be presented to the person. In embodiments, the content may relate to the physical location. In other embodiments, the content does not necessarily relate to the physical location. In instances where the physical location is selected based on personal information and the content does not relate to the location, the location may have been selected because the location is of the type that the person may spend more time viewing or interacting with content of the type to be presented.

In embodiments, a method of presenting digital content in a FOV of a HWC 102 may include identifying that the HWC 102 has arrived at a physical location, wherein the physical location is pre-determined based on personal information relating to the person wearing the HWC, and presenting the digital content in relation to an attribute in the surroundings where the attribute was pre-selected based on the personal information. The personal information may relate to personal attributes, demographics, behaviors, prior visited locations, stored personal locations, preferred locations, travel habits, etc. For example, the person wearing the HWC 102 may frequent a venue often (e.g. a place of work), and the system may present content to the person when he arrives at the venue. The type of content may also be particular to the venue, or other location selection criteria, such that the person is more apt to view and/or interact with the content. The content, for example, may relate to services or products relating to the person's work and as such the system may present the content at or near the person's place of work under the assumption that the person is going to be more interested in content relating to his work when he is at or near his place of work. In another example, content may be presented to the person when the person is passing by a sports complex because the person is generally characterized as being interested in sports. This presentation may be based on the assumption that the person may be more interested in content presented in connection with a venue that he finds interesting.

In embodiments, the placement of the digital content may be based on the selection of an environment's attribute, which was selected based on personal information relating to the person wearing the HWC 102. The personal information may suggest that the person would be more apt to interact with content if it is presented indoors, outdoors, in a room, in a hallway, on a blank wall, over a TV, near a table, near a chair, near a vehicle, while sitting, while standing, while walking, etc. For example, a 50 year old man may be more apt to interact with content that is presented in an area where he will likely be sitting, while a 17 year old man may be more apt to interact with content while he is moving. This may cause the system to choose an internal wall of a building for the presentation to the 50 year old and an external wall of the building for the presentation to the 17 year old. The 50 year old may be more apt to interact with content presented near an entrance to his place of work and the 17 year old may be more apt to interact with content when presented proximate a vehicle. Each of these attributes near the geo-spatial location are eligible candidates for the presentation of the content and the selection of the one(s) to be used may be based on the personal information known about the person wearing the HWC 102.

FIG. 67 illustrates a content presentation technology in accordance with the principles of the present invention. FIG. 67 illustrates a person entering a location proximate to his place of work 6702. This location has been pre-selected 6704 as a physical location for the presentation of digital content in the HWC 102 based on stored personal information 6708. The physical location may be further refined by identifying a wall, object or other more specific location for the presentation of the content. For example, a work wall 6714 proximate to the geo-spatial location of work 6702 may be identified for placement of the content presentation 6712 to be viewed within the FOV of the HWC 6710. The wall may then be used as a virtual marker or a virtual marker or physical marker may be identified on the wall such that the HWC 102 identifies the marker and then presents the content proximate the marker. A virtual marker may be based on physical markers, objects, lines, figures, etc. For example, the intersection of a top edge and side edge of a doorway at the place of work may be used as a virtual marker and the digital content in the FOV of the HWC 102 may be presented proximate the intersection. A virtual marker may also be established at some point distant from an object (e.g. a foot from the intersection). A virtual marker may also be set based on the person's physical location and the sight heading of the HWC 102 (e.g. as determined by an eCompass on the HWC). For example, once the person arrives at the physical location that was pre-selected based on the person's personal information, the content may be displayed in the FOV of the HWC 102 when the HWC 102 is aligned with a predetermined direction. So, for example, if the person is standing in a hallway and then looks north the content may be displayed. In embodiments, the HWC 102 identifies a physically present attribute in the surroundings and then associates the content with the attribute such that the content appears locked to the attribute from the person's perspective. For example, the person, once at the physical location, looks north and then the HWC 102 performs an analysis of the surroundings in the north direction (e.g. by imaging the surroundings with an onboard camera) to select a physical attribute to be used as a virtual marker. In embodiments, the physical marker may be pre-determined. For example, the doorway in a particular hallway may be presented as the object to key off of when setting the virtual world-locked position of the digital content. In embodiments, the physical attribute is selected based on a pre-determined criteria. For example, the system may have a list of priority placements such as being proximate a painting, picture, television, doorway, blank wall, etc., and the head-worn computer may review the physical location and select one of the priority placements for the virtual placement of the digital content.

As illustrated in FIG. 67, the physical location of the content presentation may be dependent upon personal information particular to the person wearing the HWC 102. For example, personal information, such as gender, height, weight, age, date of birth, heritage, credit history, etc. may be used as a selection criteria for the physical location. If the person is male, aged 50, the physical location may be selected from a set of locations that generally suits a man of that age. It could be that a male of that age does not generally interact with content when it is presented proximate his home, so the home location may be eliminated from the selection. It could also be that a male of that age tends to interact with content when he is taking public transportation so locations relating to public transportation may be given a higher priority in the physical location selection process. Similarly, a male that is 17 years of age may typically interact with content when he is home so the home location may be rated high when making the selection of physical location.

As illustrated in FIG. 67, the physical location of the content presentation may be dependent upon demographic information particular to the person wearing the HWC 102. For example, demographic information, such as statistically inferred information relating to a population, may be used in the selection of the physical location. If it is determined that the person is in a population of people that moves often, votes a particular way, is within a certain age range, etc. physical locations for the presentations of the content may be dependent thereon.

As illustrated in FIG. 67, the physical location of the content presentation may be dependent upon behavior information particular to the person wearing the HWC 102. For example, if the person tends to spend money at particular establishments, eat at particular venues, drive a certain type of car, play certain sports, work particular hours, etc., the tendencies or behaviors may influence the physical location for the content presentation.

In embodiments, a person's movements may be traced to identify the areas of general or particular interest to the person. The traced movements may indicate a place of work or workday place of interest, evening or home locations, driving habits, transportation habits, store locations and identities, etc. and the traced movements may influence the physical location for the content presentation. The movements may be traced by tracing GPS movements, IMU movements, or other sensor feedback from the HWC 102 or other device, for example.

In embodiments, external user interfaces and gestures as described herein elsewhere may be used to interact with the content and/or assist in the positioning of the content. For example, the content may be set to appear when a user is at a particular location based on the user's personal traits or information and the user may then use an external user interface to interact with the content to reposition the content within the environment, for posting at another environment, sharing the content, storing the content for later viewing, etc. The content, for example, may appear in proximity to a doorway, as illustrated in FIG. 67, and the user may use an external interface or gesture to move the content from its pre-set position to an alternate position (e.g. another wall, another location on the same wall, an internal wall, an external wall, an office wall, personal wall, etc.).

In embodiments, the display presentation technologies as described herein elsewhere may be used in connection with the presentation technologies based on physical placement based on personal information. For example, the content may be presented at a physical location selected based on the person's personal information and the content may be presented to be viewed at a particular focal plane such that the user perceives it in focus when the user looks at a distance associated with the focal plane. The content may also be presented when the person is at the physical location; however, the content presentation may further be based on obstacle management technologies. In the event that the user is proximate the physical location where the content is to be presented, an evaluation of obstacles in the area may be completed and then the content presentation may be altered based on any obstacles that obscure the user's view of the content presentation location.

In embodiments, the content presented at a physical location based on personal information may further be positioned in the FOV of the HWC 102 based on sensor information as described herein elsewhere. For example, the sensor may indicate that the person is moving and the content may be re-positioned within the FOV, out of the FOV, or removed entirely, based on the detected movement. In the event that the person is deemed to be moving forward quickly, for example, it may be assumed that the person wants the center of the FOV clear so the content may be shifted towards the side of the FOV. The content may be of a type that is sensor dependent, or not sensor dependent, and it may be presented with other content that is of the opposite dependency. In embodiments, the content position may move depending on the sight heading and if the sight heading is rapidly moving the position of the content in the FOV may move but the positioning may also be damped, as described herein elsewhere. The physical location presentation based on personal information may be presented in a ‘side panel’ such that it is presented when the person looks to the side or turns his head to a side when the person is at the physical location.

In embodiments, eye imaging and sight heading technologies as described herein elsewhere may be used in connection with the physical location content presentation based on personal information. For example, the content may be ready for presentation once the person has reached the physical location identified but the presentation may be conditioned on the person looking in a particular direction. The direction may be indicative of the person's eye heading or sight heading.

Another aspect of the present invention relates to providing a user interface for a participant, such as a friend or other affiliated person, such that the participant can send content to a wearer of a HWC 102 to be presented at a physical location selected by the participant. The user interface may be a selectable criteria presented when the participant is sending content to a friend. For example, the participant may want to send a video to a friend from the participant's phone, HWC, or other computing system, and the participant may select an option to have the content presented at a point in time when the friend is in proximity to a physical location. Similar to other embodiments disclosed herein elsewhere, the user interface may further provide for the selection of an attribute or attribute type to target a more particular area proximate the geo-spatial location. For example, the friend may indicate in the user interface that the content is to be delivered in an office, internal wall, external wall, etc. proximate the geo-spatial location. In embodiments, a particular attribute may be targeted, such as a particular wall or near a particular window. In other embodiments, the attribute may be a type of attribute, such as a non-specific wall or doorway. Setting a type of attribute allows flexibility in that the HWC 102 can then select the particular attribute for placement of the content. The placement selection may be based on a priority set by the sending participant or user, for example. The presentation process may further involve presenting the content influenced by the recipient's personal information or other information as disclosed herein. For example, the participant may select to send the video to a friend with a presentation setting such that the content is presented near the person's place of work, coffee shop, or other location on the way to the place of work.

FIG. 68 illustrates a presentation process that involves providing a content sender participant with a user interface 6808 such that the sender can select presentation location criteria. The criteria may include a map, a list of common locations (e.g. work, home, etc.), address entry, point of interests, prior visited locations of the recipient, etc. The criteria may further include suggested or required particular content placements, such as outside, inside, in a hall, in an office, in a room, near an elevator, near a door, above a building, on a sidewalk, on a street, proximate a vehicle, etc. The suggested or required placements may modify the geo-spatial request such that, for example, the particular suggestion may be used in connection with the geo-spatial request.

Embodiments of the present invention may involve a computer implemented process that involves receiving a personally selected geo-spatial location from a sender of digital content for the presentation of the digital content in a recipient's head-worn see-through display; and presenting, based on data indicative that the user is near the geo-spatial location, the digital content in the head-worn see-through display such that the digital content is perceived by the recipient to be associated with a physical attribute proximate the geo-spatial location. In embodiments, the personal selection may be facilitated through the use of a user interface with menu selections. The menu selections may include an indication of the recipient's frequented locations. The digital content relates to the selected geo-spatial location. For example, the digital content may be an advertisement and it may relate to a sale at a location proximate the presentation location. In embodiments, the digital content may not relate to the selected geo-spatial location. For example, a friend may have sent the recipient a virtual gift or personal message and the friend would prefer to have the recipient see, read and/or interact with the content at a pre-determined location.

In embodiments, the method further includes presenting the digital content when the head-worn computer is aligned in a pre-selected direction. For example, the sight heading, as described herein elsewhere, may align with a pre-set vector or place seen from the geo-spatial location and then the content may be presented. In embodiments, the step of presenting further includes presenting the digital content when an eye of the user is predicted to be aligned in a pre-selected direction. For example, the user's eye heading, as described herein elsewhere, such as through the use of eye imaging, may align with a pre-set vector or place seen from the geo-spatial location and then the content may be presented.

In embodiments, the user may select the digital content with an external user interface or gesture, as described herein elsewhere, to re-position or otherwise interact with the digital content. In embodiments, the step of presenting may further include identifying a potentially obstructive view object, as described herein elsewhere, and altering the digital content to indicate the potentially obstructive view. In embodiments, the step of presenting may include altering a position of the content presentation based on sensor feedback, as described herein elsewhere. For example, the sensor feedback may be indicative of the user moving forward quickly so the content may be shifted towards an edge of the FOV of the HWC to provide the user with a more clear view of his surroundings. In embodiments, the step of presenting may also include presenting the content at a location based on the recipient's personal information, or on other information as described herein.

Another aspect of the present invention relates to a user presetting preferred content receipt physical locations based on the type of content received. A HWC 102 user may preset physical locations, including geo-spatial locations and particular locations in proximity to the geo-spatial location, for the presentation of certain types of content. For example, the user may set a location near or at his place of work for the presentation of work content. The user may set nutrition and exercise content for presentation at the gym or home or while out dining. This technology provides the user with a way of organizing the presentation of content such that the user will be more apt to review and/or interact with the content and thus the content may be of more use to the user.

FIG. 69 illustrates various locations where a user may want certain types of content presented in the see-through display of the HWC 102. The user may select work 6902, home 6912, a vehicle 6904, a road 6908, a gym 6910, etc. and each location may be associated with a content type. The content may or may not relate specifically to the location and one type of content may be selected to be presented at multiple locations.

In embodiments, a computer implemented process in accordance with the principles of the present invention involves establishing a plurality of content presentation settings wherein each of the plurality of settings includes an indication of a physical location where a recipient desires a type of digital content to be presented in the recipient's head-worn see-through display; and presenting content intended for delivery to the recipient when data indicates that the head-worn see-through display is proximate one of the plurality of physical locations when the content type corresponds to the type of digital content to be presented at the physical location based on the content presentation setting.

In embodiments, the plurality of content presentation settings may be established through the recipient's selections on a settings user interface. The plurality of content presentation settings may be established based on the recipient's prior interactions with digital content. The presented content may relate to the physical location where presentation is made; the presented content may not relate to the physical location where presentation is made. The indication of physical location may include a geo-spatial location and an object attribute type. The object attribute type may be a specific object's attribute. The step of presenting may also include presenting the content when data indicates that the head-worn see-through display is sight heading aligned with a selected object attribute. The step of presenting may also include presenting the content when data indicates that the head-worn see-through display is eye heading aligned with a selected object attribute. The process may also include receiving an indication that the recipient has selected the content with an external user interface to re-position the digital content. The step of presenting may also include identifying a potentially obstructive view object and altering the content to indicate the potentially obstructive view. The step of presenting may further include altering a position of the presentation based on sensor feedback. The sensor feedback may be indicative of the user moving forward. The step of presenting may also include presenting based on the recipient's personal information. The step of presenting may also include presenting based on a sender's location specific presentation request. Embodiments of the present invention involve processes described herein elsewhere.

Another aspect of the present invention relates to providing supplemental content to provide hints, guidance, and/or directions to a physical location where primary content may be presented. There are situations where content is scheduled to be presented to the wearer of a HWC 102 when the wearer enters a region or physical location or looks towards a physical location and there are times when it is useful to provide additional information outside or inside of the region to provide the wearer with indications that the primary content may be presented. The supplemental content may indicate that the wearer has a personal message waiting to be viewed, an advertisement waiting to be viewed, or other information waiting to be viewed.

FIG. 70 illustrates hint content 7002 and primary content 7004. The hint content, or supplemental content, may be set to be presented to the wearer of a HWC 102 when the wearer enters a physical location or region. The hint content may then provide guidance, directions or other indications relating to the primary content 7004. The hint content 7002 may be presented at locations proximate a location where the primary content 7004 is to be presented or the hint content 7002 may be set to be presented at locations remote to the location at which the primary content 7004 is set to be presented. For example, the wearer may be walking down a street and look up the side of a building where he will see presented to him in his HWC 102 display virtual hint content 7002 that provides him with an indication that the primary content 7004 is nearby and ready to be presented once he gets to or looks at the associated pre-set physical location or environmental attribute.

In embodiments, a computer operated process may involve pre-determining a physical environment position for the presentation of primary virtual content, wherein the primary virtual content is presented in a see-through head-worn display; and pre-determining a position for each of a plurality of directionally informative content, wherein each of the plurality of directionally informative content is associated with a different physical environment position and indicates to a person wearing the see-through head-worn computer in what direction the primary virtual content will be found. The step of pre-determining the physical environment position for the presentation of the primary virtual content may involve determining the physical environmental position based on personal information relating to the person. The step of pre-determining the physical environment position for the presentation of the primary virtual content may involve determining the physical environmental position based on a content sender's requested delivery criteria. The step of pre-determining the physical environment position for the presentation of the primary virtual content may involve determining the physical environmental position based on the person's pre-set content delivery preferences. In embodiments, each of the plurality of directionally informative content may include video content. In embodiments, each of the plurality of directionally informative content may include an image. The physical environment position for the presentation of primary virtual content may include a geo-spatial position, environment attribute type, specific environment attribute, etc. In embodiments, the primary virtual content relates to the physical environment position for the presentation of primary virtual content. In other embodiments, the primary virtual content does not relate to the physical environment position for the presentation of primary virtual content. The primary virtual content may be presented when data indicates that the head-worn see-through display is proximate the physical environment position for the presentation of primary virtual content. The step of presenting may also include presenting the content when data indicates that the head-worn see-through display has an eye heading aligned with a selected object attribute. The step of presenting may also include presenting the content when data indicates that the head-worn see-through display has a sight heading aligned with a selected object attribute. In embodiments, the process may also include receiving an indication that the recipient has selected the primary virtual content with an external user interface to re-position the digital content. In embodiments, the step of presenting may also include identifying a potentially obstructive view object and altering the primary virtual content to indicate the potentially obstructive view. The step of presenting may also include altering a position of the presentation based on sensor feedback. The sensor feedback may be indicative of the user moving forward. Embodiments of the present invention involve processes described herein elsewhere.

Another aspect of the present invention relates to sending a group message to a plurality of recipients where the message is presented to each of the group's recipients when each individual recipient enters a respective physical location. The physical location at which the message is presented may be based in part on the sender's preferences and in part on the recipient's preferences. As described herein, senders and recipients may have physical location presentation preferences and the system may reconcile these preferences before presenting the content. In a group message situation, in embodiments, a server may be involved in reconciling the sender's presentation preferences and each of the recipient's preferences.

FIG. 71 illustrates a group message 7110 being sent to a plurality of recipients 7112. The group message is communicated through a server 7102 and the server reconciles a set of sender presentation preferences with a set of recipient presentation preferences for each of the group of recipients.

In embodiments, a computer operated process may involve receiving content to be delivered to a plurality of recipients, wherein each recipient of the plurality of recipients has a preference for the physical location at which the content is to be presented in the recipient's see-through head-worn display and a sender of the content has a preference for the physical location at which the content is to be presented to each recipient of the plurality of recipients; identifying a final physical location for the presentation of the content for each recipient of the plurality of recipients, wherein the final physical location is based on both the recipient's preference and the sender's preference; and causing the content to be presented to each recipient of the plurality of recipients when each recipient is proximate the final physical location identified for the recipient. In embodiments, the sender's preference overrides the recipient's preference. In embodiments, the recipient's preference overrides the sender's preference. In embodiments, the final physical location represents a location that is within acceptable positions identified for the recipient and is a priority position for the sender. In embodiments, the physical location preference for at least one recipient of the plurality of recipients is established based on personal information relating to the at least one recipient. In embodiments, the physical location preference for at least one recipient of the plurality of recipients is established based on the at least one recipient's selections. In embodiments, the physical location preference for the sender is established based on the sender's selection in a user interface. The physical location for at least one recipient of the plurality of recipients may include a geo-spatial position. The physical location for at least one recipient of the plurality of recipients may include an environment attribute type. The physical location for at least one recipient of the plurality of recipients may include an environment attribute. The content may or may not relate to the physical location for at least one recipients of the plurality of recipients. The content may be presented when data indicates that the head-worn see-through display is proximate the final physical location for each of the recipients of the plurality of recipients. In embodiments, the step of presenting may also include presenting the content when data indicates that the head-worn see-through display has an eye heading aligned with a selected object attribute. The step of presenting may also include presenting the content when data indicates that the head-worn see-through display has a sight heading aligned with a selected object attribute. The process may also include receiving an indication that at least one recipient of the plurality of recipients has selected the content with an external user interface to re-position the digital content. In embodiments, the step of presenting may also include, for at least one recipient of the plurality of recipients, identifying a potentially obstructive view object and altering the primary virtual content to indicate the potentially obstructive view. The step of presenting may also include altering a position of the presentation based on sensor feedback. The sensor feedback may be indicative of the user moving forward. In embodiments, the content also has a presentation location preference and the step of identifying the final presentation location for each recipient of the plurality of recipients may also include presenting based on the content presentation location preference. Embodiments of the present invention involve processes described herein elsewhere.

FIG. 72 illustrates a system that reconciles recipient preferences 7104, sender preferences 7108 and content preferences 7202 when a group message is sent and/or when content is shared. The shared content 7204 may be associated with its own location presentation settings or preferences. When it is sent to the share recipients 7208 it may go through a server system where the various preferences are reconciled before the locations for the presentation of the share content 7204 for each respective recipient is set. Content preferences 7202 may be set by an owner of the content or other party interested in the content such that the content is presented in association with certain physical location and possibly not presented with other physical locations. For example, the content may be a restaurant advertisement and the content preferences may include preferred locations proximate the actual restaurant and restrictions so the advertisement is not presented in connection with certain areas because those areas are not of the quality associated with the restaurant.

Another aspect of the present invention relates to the activation of a marker recognition system for a HWC 102. The marker recognition activation process includes identifying when the HWC 102 is physically proximate a location where content is to be presented in the HWC 102. This process can save power by reducing the amount of time the marker recognition system is active. As described in connection with other embodiments described herein, content may be set to be presented to a HWC 102 when the HWC 102 is proximate a physical location. Further embodiments may involve identifying to the HWC 102 at what location(s) it should expect to find markers for the presentation of content. With the locations pre-identified to the HWC 102 the HWC 102 can activate the marker recognition system when proximate the pre-identified locations.

In a further embodiment, a haptic alert may be presented to the user when the HWC nears a geospatial location that has associated content to be presented to the user. The haptic alert can be in the form of a vibration, electric stimulus or a change of the displayed image such as a flash, etc.

FIG. 73 illustrates a marker recognition activation system according to the principles of the present invention. Content is set to be presented to the HWC 102 at a physical location 7302, as described herein. A marker recognition activation zone 7304 is established for the HWC 102 such that the HWC 102 activates the marker recognition system when the HWC 102 is within the zone. The HWC 102 may deactivate the marker recognition system when the HWC 102 leaves the activation zone.

In embodiments, a computer operated process may involve pre-setting a geo-spatial location where content will be displayed to a user of a see-through head-worn display; establishing a region proximate the geo-spatial location; and causing a marker recognition system of the head-worn see-through display to activate when data indicates that the see-through head-worn display is within the region, wherein the marker recognition system monitors a surrounding environment to identify a marker that will act as a virtual anchor for the presentation of the content. In embodiments, the marker may be a pre-established physical attribute. In embodiments, the marker is a priority marker selected from a plurality of markers, wherein the priority marker was identified by scanning the surrounding environment in a search for the plurality of markers. In embodiments, the geo-spatial location may be selected based on personal information known about the user. In embodiments, the geo-spatial location may be selected based on a presentation preference setting established by the user. In embodiments, the geo-spatial location may be selected based on a preference of a sender of the content. In embodiments, the geo-spatial location may be selected based on a preference setting of the content. In embodiments, the content may or may not relate to the geo-spatial location. In embodiments, the content may have been sent by another user characterized as a friend of the user through a known affiliation. The content may be a text message, image file, video, etc. In embodiments, informational content may presented to the user in the see-through head-worn display to indicate to the user that primary content is queued for presentation and will be presented when the user goes to the presentation. The informational content may also include an indication of a direction in which the user will be presented with the content. Embodiments of the present invention involve processes described herein elsewhere.

FIG. 74 illustrates preloaded HWC 102 content 7402 associated with a tag, metadata, etc. 7404 that indicates to the HWC 102 at what physical location to present the content. The tag 7404 may have pre-reconciled preferences based on the recipient's preferences 7104, sender preferences 7108 and content preferences 7202.

Another aspect of the present invention relates to confirming that content intended to be presented in a HWC 102 when the HWC 102 is proximate a physical location is actually presented and/or viewed. Senders of content tend to be interested to know if the content was delivered, presented, viewed, interacted with, etc. This may be important to advertisers, businesses, individuals, etc. With content intended to be delivered at a point in the future and dependent on the user being proximate a physical location it may be even more important to have a presentation confirmation system in accordance with the principles of the present invention.

FIG. 75 illustrates a presentation confirmation system in accordance with the principles of the present invention. The content is presented to the user 7208 of the HWC 102 when the user 7208 arrives at the pre-determined physical location 7802 and then a confirmation of the presentation is sent to a server or other computing system. Once communicated from the HWC 102, the confirmation may be passed on to the sender or other interested party to confirm that the content was presented at the intended location.

FIG. 76 illustrates a confirmation system in accordance with the principles of the present invention. The content is presented to the user 7208 of the HWC 102 when the user 7208 arrives at the pre-determined physical location 7802. The sight heading or eye heading or persistence of either is then recorded and communicated 7602 from the HWC 102 as a confirmation.

In embodiments, a computer operated process may involve pre-setting a geo-spatial location where content will be displayed to a user of a see-through head-worn display; establishing a region proximate the geo-spatial location; presenting to the user in the see-through head-worn display the content when data indicative that the head-worn see-through display has entered the region; and causing a presentation confirmation to be communicated to a server based on the fact that the content was presented in the head-worn see-through display. In embodiments, the user's identity may be verified through biometric information such that the presentation confirmation represents a confirmation that the content was presented to a verified user. The user's identity may have been identified through eye imaging. In embodiments, the step of presenting to the user may also involve presenting when data indicative that the head-worn see-through display was aligned with a pre-established sight heading. The step of presenting to the user may also include presenting when data indicative that the user's eye was aligned with a pre-established eye heading. The presentation confirmation may be communicated from the server to a sender of the content. The sender may be a person characterized as a friend of the user through a known affiliation, an advertiser, etc. The presentation confirmation may include a persistence statistic indicative of how long the person viewed the content. The persistence statistic may be based on a recorded sight heading relating to the head-worn see-through display. The persistence statistic may be based on a recorded eye heading relating to the user's eye position. In embodiments the geo-spatial location may be selected based on personal information known about the user. The geo-spatial location may be selected based on a presentation preference established for the user. The geo-spatial location may be selected based on a presentation preference of a sender of the content. The geo-spatial location may be selected based on a preference setting relating to the content. Embodiments of the present invention involve processes described herein elsewhere.

Another aspect of the present invention relates to determining a distance between a head-worn display and an object in the environment and then presenting content in the head-worn display based on the determined distance. There are many situations where one would like to display content in a head-worn see-through display at a perspective, size, and focus such that the person wearing the head-worn display has a perspective that the content is at a particular location in the environment. As described herein elsewhere, there are times when one wants to align digital content with an object in the environment proximate to the user, but it can be difficult to estimate how far away the object is from the user. It can be important to make a good estimation of distance to the object such that any proximately associated content appears in the correct perspective and focus. In embodiments, known objects in the environment proximate the user are recognized to assist with the distance determination. For example, a HWC 102 may have access to a database of objects (e.g. on-board, server based, etc.) and the camera on the HWC 102 may be activated to look for any appearance of the objects when it is desirable to display content that is intended to have the appearance that the content is proximate an object in the environment. Once the camera system recognizes one or more known objects, an evaluation of how far each object is from the user may be done based on the known objects known physical dimensions. The physical dimensions may be used as a reference when reviewing the size of the objects in the image.

FIG. 77 illustrates a situation where there is an object 7704 in the environment proximate the user of a HWC 102. The user can see through the display in the HWC 102 and see the object 7704 in the field of view 7702 of the display. A camera mounted on the HWC 102 captures an image of the object 7704. The image is then processed (e.g. on-board the HWC 102, at a server, etc.) where the object 7704 is recognized as a known object with known dimensional and/or perspective information 7710. The known object and dimensional and/or perspective information 7710 may be found in a database 7708 of such information. Once the object is identified as known a comparison of its image captured dimensions may be compared with the known object dimensions 7708 such that an estimate of the object's distance from the HWC 102 can be made.

In embodiments, the known objects may be pre-identified and they may be generalized, standard, generic, specific, etc. For example, the known objects may be a doorway, mailbox, window, window frame, house siding, brick, light switch, light post, telephone poll, road sign, speed limit sign, reflector, road reflector, vehicle, building, tile, head size, inter-pupil distance, etc.

With the distance to the known object estimated, the digital content may be presented in the field of view of the head-worn display such that it appears in a focal plane in relation to the object in the environment. In embodiments, the focal plane may be defined by a convergence plane, a perspective viewing angle, object size, focal distance, etc. For example, with the distance to the object estimated, the content may be presented such that the content's size is based on the distance, so the further away the object is, the smaller the content will appear. As another example, with the distance to the object estimated, the content may be presented in a similar perspective or angle as the object. As another example, the content may be presented at a position in the head-worn display field of view based on an estimated convergence of the user's eyes, which is based on the distance. As another example, the content may be presented such that it comes into proper focus when the user's eye focuses at the distance or other related distance. As another example, the content may be presented based on one or more of the factors of size, convergence, perspective, focal distance, etc.

By way of further example, if the object in the environment is a light switch and the light switch has a cover plate, the HWC 102 system may recognize the cover plate as a standard sized cover plate and may look up the dimensions of the cover plate. Then the system may make a comparison of the size of the plate in the image and the standard physical size of the plate and make an estimate of distance. Then the HWC 102 may present content in the head-worn display field of view where the content's size is altered to appear relatively sized with respect to the plate at the distance.

Another aspect of the present invention relates to estimating distances from a head-worn computer based on the distance between known objects in an environment. As illustrated herein, known object dimensions can be used to estimate distance and assist with the contextual presentation of content in an augmented reality view using a see-through head-worn display. Similarly, many objects in the environment have known or standardized distances between them. Light poles along a road, for example, are generally separated by a standard distance. Imaging the separation and comparing the separation to a known, standardized, generalized, etc. distance can be used to understand distances into the environment. One may want content to appear to be in between the two poles, for example, and with the distance estimated, the content may be positioned, sized, focused accordingly. The objects may be light poles, telephone poles, buildings, sidewalk segments, etc.

Another aspect of the present invention relates to presenting content in a see-through head-worn display based on an estimation of a distance to a known object in the environment when the object is imaged at an off-normal perspective. The process may involve capturing an image of an object in an environment proximate a person wearing a head-worn display, recognizing the object as a known object with known physical dimensions, recognizing that the object is not at a normal angle (i.e. not parallel to the image capture device) in the image, analyzing the image of the object in relation to the known physical dimensions to determine an approximate off-normal angle of the object in the image, determine an approximate distance between an image capture device used to capture the image of the object and the object based on the known physical dimensions as applied using a model based on the off-normal angle of the object in the image, and displaying content in the head-worn display at a position apparently proximate the object and at a focal plane relative to the approximate distance.

In embodiments, the captured images of objects in the environment may not be captured ‘straight-on’ and the amount of off-angle capture will change the appearance of the object. For example, it may be keystoned, of a perspective view, etc. In embodiments, once the object is recognized as a known object and it is recognized that it is off-angle, the object's image may be normalized or straightened such that its dimensions can be compared to its standard dimensions in the process of estimating the distance to the object.

FIG. 78 illustrates a situation where the object 7704 in the environment is viewed through the field of view 7702 and also captured at an off-angle. The object 7704 appears at a perspective angle and it also appears keystoned. Image processing may be used to estimate the shapes normal view and also assess its dimensions for the distance estimation. In embodiments, to assist in the object recognition, object artifacts 7804 may be assessed. In a further embodiment, an associated object 7802 (e.g. the pole holding the stop sign) may be used to assist in the object's recognition. In embodiments, the artifact 7804 or associated object 7802 may be used for the distance estimation. For example, once one recognizes that the object is a stop sign one might use the sign post for the distance estimation because it does not appear as distorted because of its basic shape. One might also use its physical dimensions as they relate to the primary object for the distance determination. For example, stop signs are generally mounted at a standard height and the distance of the pole from the ground to the sign may be used in the distance estimation.

Another aspect of the present invention relates to using the ‘pose’ or perspective view angle of an object in the environment for alignment, shaping, sizing, and/or other adaptation of digital content presented in the field of view of the head-worn display such that the content appears to properly fit into the see-through scene. It can be difficult to place, arrange, shape, size and focus augmented reality content as an overlay in an unfamiliar see-through environment. In embodiments, the HWC 102 looks for known objects in the environment in an attempt to properly characterize the positional pose of the object such that digital content can be adapted to fit the scene. For example, a light switch plate may be recognized as a known object with known dimensions and the HWC 102 system may recognize that the plate is at an off-normal angle from the capture system. The perspective view of the plate, including keystoning, may be determined such that the content can be adapted to fit into the same or related perspective, which may include modifying the content's shape, perspective shape, keystone, size, focus plane, etc. such that it appears to match the scene from the user's perspective.

FIG. 79 illustrates a situation where the object 7704 is being viewed through the see-through display field of view 7702 at a non-normal angle such that the object 7704 appears in a perspective view. In this embodiment, the object 7704 is a known and recognized object with known dimensions. The object is imaged and the image is processed to understand, with comparison to the known dimensions, the nature of the perspective view. Then, the content can be manipulated or chosen to match the perspective view of the object from the user's perspective. The object may be adapted to larger, smaller, greater angle, less angle, etc. depending on the intended reference surface and then the perspective aligned content 7902 can be presented in the field of view in relation to the object such that the content appears consistent with the user's perspective of the object in the scene.

In embodiments, a recognized known object may be selected as a reference when selecting a surface for content association. For example, in an unfamiliar scene, the HWC 102 may be assessing where to place certain content, such as a wall. When making the assessment, it may be important to select a reference that provides perspective viewing angles, so the HWC 102 may look for known objects. This can be especially useful in situations where wall lines are not available for analysis. Once the HWC 102 recognizes a known object and recognizes a related surface suitable for content association, the process of selecting the related surface and adjusting the content to suit the scene can be executed.

Another aspect of the present invention relates to confirming a distance estimation by imaging and evaluating the known object. As disclosed herein elsewhere, there are situations where the content is going to be presented at a distance based on a geo-spatial location. When the geo-spatial location of the head-worn computer and the geo-spatial location of the desired content association are both known, the content can be manipulated such that it appears to fit the scene at that distance. As described herein elsewhere, an issue arises when, for example, the user does not have an unobstructed view of the geo-spatial location for the content presentation. In embodiments, the HWC 102 may confirm that the user has an unobstructed view of the geo-spatial location by recognizing a known object at or near the distance prescribed by the difference in geo-spatial locations and determining a distance to the object. For example, if content is to be presented to appear to be at a distance of 100 feet from the user at an angle in front of the user, the HWC may look for objects in the prescribed direction and then use the technologies described herein to determine distance to the objects in an assessment of the unobstructed view. If a known object is on a surface that appears to be blocking the user's view of the prescribed geo-spatial location for the presentation association, then obstructed view techniques (as described herein elsewhere) may be used to alter the presentation of the content.

Another aspect of the present invention relates to minimizing distance estimation errors when assessing a distance from a head-worn computer to an object in the environment when the distance assessment is based on a known object's physical dimensions. It is possible that when the HWC 102 recognizes an object as a known object with known physical properties that it got it wrong and the system made the wrong association between the image of the object and the object identification. In embodiments, to minimize this problem, more than one object is recognized and a statistical model is used to assess the multiple distances to the multiple objects. For example, effectively, a map of the known object distances may be developed analyzed for anomalies and the anomalies may then be removed or minimized. For example, objects in the environment will be connected through various materials in the environment and if the map is completed and one or more of the objects does not fit an expected shape than the one or more objects may be disregarded or minimized in the evaluation.

The process for determining distances to objects may recognize that different objects will be linked through physical structures in the environment. The process may involve identifying multiple objects that are linked into a pattern to identify which objects should be included in a statistical analysis. In embodiments, this may be in the form of identifying a pattern of perceived sizes of similar objects that imply a pattern of distances for the objects. For example, the objects can be identified to be on the same plane or on the same line. This pattern recognition provides the intelligence to improve the accuracy of the distance inference in this method. So, for example, if you are looking at telephone poles on a straight road, you can tell that the poles are all linked since they are in a line. The distances to each pole should then be progressively farther away based on height. If one doesn't fit into the pattern, then it likely is a short pole or the pole is located in a depression. Since it may be difficult to determine why this object doesn't fit the pattern, it should be ignored in calculations of distance and presentation focal planes.

As another example, if three light switches are on the same plane, and the one that appears to be in the middle is the largest (or it calculates as being located the closest), then it is likely a physically larger size. Since this object is apparently an object without a known set of dimensions, it may be ignored in the calculation of distance and the other two may be used to determine distances.

As another example, if the floors of a building, as viewed from outside of the building, are being used to determine distance, and the top floors appear to be closer than the bottom floors, this is likely because they have higher ceilings. In this case, the top floors may be eliminated from the calculation of distance. Alternately, a new pattern may be identified with multiple objects included. For example, distance calculations could include the lower floors in one group and the upper floors in another group.

In embodiments, image analysis may also suggest when one object is in front of another and if the distance calculations suggest otherwise, one or both of the objects may be disregarded as distance markers. For example, objects floating on a non-moving body of water will all be at the same height. As a result, any object that appears to be in front of another object should calculate to be closer than the other object. If the one in front calculates to be farther away than one or both of the objects is probably not a known object with known dimensions and either one or both should be disregarded.

Moving objects tend not to be good for marking non-moving surface distances and one aspect of the invention removes moving objects from consideration even when they are known objects with known physical dimensions. In embodiments, multiple frames of the environment may be captured and analyzed to determine if a known object is in motion. If it is in motion and the process is attempting to identify distance to a non-moving object or surface, the moving object may be disregarded from the distance calculation.

Although embodiments of HWC have been described in language specific to features, systems, computer processes and/or methods, the appended claims are not necessarily limited to the specific features, systems, computer processes and/or methods described. Rather, the specific features, systems, computer processes and/or and methods are disclosed as non-limited example implementations of HWC.

All documents referenced herein are hereby incorporated by reference. 

What is claimed is:
 1. A system comprising: an optics module comprising: an illumination light source; a splitter comprising a polarizer and a mirror; a reflective display configured to receive illumination light from the illumination light source via a quarter-wave plate and further via the polarizer, and further configured to reflect image light toward a user's eye via the quarter-wave plate; a first infrared light source configured to present first infrared light to the user's eye via the mirror for reflection in the user's eye; and a first sensor configured to receive, via the mirror, the first infrared light reflected in the user's eye.
 2. The system of claim 1, wherein: the system further comprises a wearable head device, the wearable head device comprises an upper optics module comprising the optics module, and the wearable head device further comprises a lower optics module disposed between the user's eye and the upper optics module.
 3. The system of claim 1, wherein the mirror comprises a hot mirror.
 4. The system of claim 1, wherein the image light is polarized and the first infrared light is unpolarized.
 5. The system of claim 1, wherein the optics module further comprises a second infrared light source configured to present second infrared light to the user's eye via the mirror for reflection in the user's eye, wherein: the sensor is further configured to receive, via the mirror, the second infrared light reflected in the user's eye, and the first infrared light comprises infrared light of a first wavelength and the second infrared light comprises infrared light of a second wavelength different from the first wavelength.
 6. The system of claim 1, wherein the optics module further comprises a second sensor configured to receive, via the polarizer, image light reflected in the user's eye.
 7. The system of claim 6, wherein the second sensor is configured to receive the image light concurrently with the first sensor receiving the first infrared light.
 8. A method comprising: receiving, at a reflective display of an optics module, illumination light from an illumination light source via a quarter-wave plate and further via a polarizer, in response to the reflective display receiving the illumination light, reflecting image light toward a user's eye via the quarter-wave plate; presenting, via an infrared light source, first infrared light to the user's eye via a mirror for reflection in the user's eye; and receiving, at a first sensor, via the mirror, the first infrared light reflected in the user's eye, wherein the optics module comprises a splitter, the splitter comprising the polarizer and further comprising the mirror.
 9. The method of claim 8, wherein: the user is a user of a wearable head device comprising an upper optics module comprising the optics module, and the wearable head device further comprises a lower optics module disposed between the user's eye and the upper optics module.
 10. The method of claim 8, wherein the mirror comprises a hot mirror.
 11. The method of claim 8, wherein the image light is polarized and the first infrared light is unpolarized.
 12. The method of claim 8, wherein the optics module further comprises a second infrared light source, and wherein the method further comprises: presenting, via the second infrared light source, second infrared light to the user's eye via the mirror; and receiving, at the sensor, via the mirror, the second infrared light reflected via the user's eye, wherein the first infrared light comprises infrared light of a first wavelength and the second infrared light comprises infrared light of a second wavelength different from the first wavelength.
 13. The method of claim 8, further comprising: receiving, at a second sensor, via the polarizer, image light reflected in the user's eye.
 14. The method of claim 13, wherein the second sensor receives the image light concurrently with the first sensor receiving the first infrared light. 